Journal articles: 'Surface passivation'

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Tyagi, Pawan. "GaAs(100) Surface Passivation with Sulfide and Fluoride Ions." MRS Advances 2, no. 51 (2017): 2915–20. http://dx.doi.org/10.1557/adv.2017.380.

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ABSTRACTInteraction of GaAs with sulfur can be immensely beneficial in reducing the deleterious effect of surface states on recombination attributes. Bonding of sulfur on GaAs is also important for developing novel molecular devices and sensors, where a molecular channel can be connected to GaAs surface via thiol functional group. However, the primary challenge lies in increasing the stability and effectiveness of the sulfur passivated GaAs. We have investigated the effect of single and double step surface passivation of n-GaAs(100) by using the sulfide and fluoride ions. Our single-step passivation involved the use of sulfide and fluoride ions individually. However, the two kinds of double-step passivations were performed by treating the n-GaAs surface. In the first approach GaAs surface was firstly treated with sulfide ions and secondly with fluoride ions, respectively. In the second double step approach GaAs surface was first treated with fluoride ions followed by sulfide ions, respectively. Sulfidation was conducted using the nonaqueous solution of sodium sulfide salt. Whereas the passivation steps with fluoride ion was performed with the aqueous solution of ammonium fluoride. Both sulfidation and fluoridation steps were performed either by dipping the GaAs sample in the desired ionic solution or electrochemically. Photoluminescence was conducted to characterize the relative changes in surface recombination velocity due to the single and double step surface passivation. Photoluminescence study showed that the double-step chemical treatment where GaAs was first treated with fluoride ions followed by the sulfide ions yielded the highest improvement. The time vs. photoluminescence study showed that this double-step passivation exhibited lower degradation rate as compared to widely discussed sulfide ion passivated GaAs surface. We also conducted surface elemental analysis using Rutherford Back Scattering to decipher the near surface chemical changes due to the four passivation methodologies we adopted. The double-step passivations affected the shallower region near GaAs surface as compared to the single step passivations.

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Kabalan, Amal. "A Comparative Study on the Effects of Passivation Methods on the Carrier Lifetime of RIE and MACE Silicon Micropillars." Applied Sciences 9, no. 9 (April 30, 2019): 1804. http://dx.doi.org/10.3390/app9091804.

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Silicon micropillars have been suggested as one of the techniques for improving the efficiency of devices. Fabrication of micropillars has been done in several ways—Metal Assisted Chemical Etching (MACE) and Reactive Ion Etching (RIE) being the most popular techniques. These techniques include etching through the surface which results in surface damage that affects the carrier lifetime. This paper presents a study that compares the carrier lifetime of micropillars fabricated using RIE and MACE methods. It also looks at increasing carrier lifetime by surface treatment using three main approaches: surface passivation by depositing Al2O3, surface passivation by depositing SiO2/SiN, and surface passivation by etching using KOH and Hydrofluoric Nitric Acetic (HNA) solution. It was concluded that passivating with SiO2 and SiN results in the highest carrier lifetime on the MACE and RIE pillars.

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Clerix, Jan-Willem J., Golnaz Dianat, Annelies Delabie, and Gregory N. Parsons. "In situ analysis of nucleation reactions during TiCl₄/H₂O atomic layer deposition on SiO₂ and H-terminated Si surfaces treated with a silane small molecule inhibitor." Journal of Vacuum Science & Technology A 41, no. 3 (May 2023): 032406. http://dx.doi.org/10.1116/6.0002493.

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Small-molecule inhibitors have recently been introduced for passivation during area-selective deposition (ASD). Small silanes like ( N, N-dimethylamino)trimethylsilane (DMATMS) selectively react with −OH sites on SiO2 to form a less reactive –OSi(CH3)3 terminated surface. The –OSi(CH3)3 surface termination can inhibit many atomic layer deposition (ALD) processes, including TiCl4/H2O ALD. However, the mechanisms by which ALD is inhibited and by which selectivity is eventually lost are not well understood. This study uses in situ Fourier-transform infrared spectroscopy to probe the adsorption of DMATMS on SiO2 and the subsequent reactions when the passivated surface is exposed to TiCl4/H2O ALD. The chemisorption of DMATMS on isolated –OH groups on SiO2 is shown to inhibit the reaction with TiCl4. Further, we find that starting with an inherently inhibiting H-terminated Si surface, DMATMS can also react with residual –OH groups and reduce the extent of nucleation. Finally, using Rutherford backscattering spectrometry, the effectiveness of DMATMS passivation on SiO2 and H-terminated Si is quantified during extended ALD cycle numbers. The insight into the mechanisms of passivation by DMATMS and passivation loss can enable the rational design of highly selective ASD processes by carefully matching compatible surfaces, passivating agents, and ALD precursors.

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Jones, K. M., M. M. Al-Jassim, and B. L. Soport. "TEM investigation of hydrogen-implanted polycrystalline Si." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 868–69. http://dx.doi.org/10.1017/s0424820100088658.

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Hydrogen implantation for passivating grain boundaries and dislocations in polycrystalline silicon solar cells was studied by TEM and HREM. Back-surface passivation is being investigated because studies have shown that front-side passivation causes serious surface damage with resultant surface recombination velocities as high as 7 x 107 cm/sec. Front-side hydrogenation also restricts solar cell fabrication processes. Since the passivation of defects must occur within the entire volume of the cell, particular emphasis was placed on the depth distribution of hydrogen. The hydrogen implantation was carried out In a Kaufman ion beam system using a beam energy of 0.5-1.5 keV and a beam current of 55 mA for 15 minutes.

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Özeren, Mehmet Derya, Áron Pekker, Katalin Kamarás, and Bea Botka. "Evaluation of surface passivating solvents for single and mixed halide perovskites." RSC Advances 12, no. 44 (2022): 28853–61. http://dx.doi.org/10.1039/d2ra04278a.

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Various surface passivating solvents with different functional groups were used to investigate solvent–perovskite interactions. The identification of the underlying mechanisms provides insight for new surface passivation strategies.

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Vermang, Bart, Aude Rothschild, Karine Kenis, Kurt Wostyn, Twan Bearda, A. Racz, X. Loozen, et al. "Surface Passivation for Si Solar Cells: A Combination of Advanced Surface Cleaning and Thermal Atomic Layer Deposition of Al₂O₃." Solid State Phenomena 187 (April 2012): 357–61. http://dx.doi.org/10.4028/www.scientific.net/ssp.187.357.

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Thermal atomic layer deposition (ALD) of Al2O3 provides an adequate level of surface passivation for both p-type and n-type Si solar cells. To obtain the most qualitative and uniform surface passivation advanced cleaning development is required. The studied pre-deposition treatments include an HF (Si-H) or oxidizing (Si-OH) last step and finish with simple hot-air drying or more sophisticated Marangoni drying. To examine the quality and uniformity of surface passivation - after cleaning and Al2O3 deposition - carrier density imaging (CDI) and quasi-steady-state photo-conductance (QSSPC) are applied. A hydrophilic surface clean that leads to improved surface passivation level is found. Si-H starting surfaces lead to equivalent passivation quality but worse passivation uniformity. The hydrophilic surface clean is preferred because it is thermodynamically stable, enables higher and more uniform ALD growth and consequently exhibits better surface passivation uniformity.

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Szuromi, Phil. "Optimizing surface passivation." Science 366, no. 6472 (December 19, 2019): 1467.5–1467. http://dx.doi.org/10.1126/science.366.6472.1467-e.

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Meiners, L. G., and H. H. Wieder. "Semiconductor surface passivation." Materials Science Reports 3, no. 3-4 (January 1988): 139–216. http://dx.doi.org/10.1016/s0920-2307(88)80008-2.

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Gaikwad, Pooja Vinod, Nazifa Rahman, Rooshi Parikh, Jalen Crespo, Zachary Cohen, and Ryan M. Williams. "Detection of the Inflammatory Cytokine IL-6 in Complex Human Serum Samples Via Rational Nanotube Surface Passivation Screening." ECS Meeting Abstracts MA2023-01, no. 9 (August 28, 2023): 1124. http://dx.doi.org/10.1149/ma2023-0191124mtgabs.

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In recent years, biosensors have emerged as a tool with strong potential in medical diagnostics. Single-walled carbon nanotube (SWCNT) based optical nanosensors have notably garnered interest due to the unique characteristics of their near-infrared fluorescence emission, including tissue transparency, photostability, and various chiralities with discrete absorption and fluorescence emission bands. The optoelectronic properties of SWCNT are sensitive to the surrounding environment, which makes them suitable for highly selective biosensing. Single-stranded (ss) DNA-wrapped SWCNTs have been reported as optical nanosensors for cancers and metabolic diseases. However, given the complexity of the human protein environment, non-specific interactions occur between SWCNT-based nanosensors and proteins. This inevitably leads to compromised selectivity of SWCNT-based nanosensors unless strategies for prevention are developed and employed. Non-covalent passivation of the ssDNA-SWCNT surface is reported as an excellent strategy to improve nanosensor selectivity in complex biological settings without causing irreversible changes to the optical properties of SWCNTs. Emerging studies have explored and successfully shown passivation using proteins and phospholipids. However, a systematic comparative study of passivating agents has not been done. In this work, we explore and compare the efficacy of select proteins, polymers, and surfactants as passivating agents. We, therefore, sought to evaluate various potential SWCNT surface passivation agents among broad classes of biomolecules and biomaterials. In the category of protein, Bovine serum albumin, dry-fat milk powder, and casein were selected due to their wide application to improve immunoassay selectivity. In the class of polymers, we selected 1 anionic and 2 cationic polymers, namely, polyethylene glycol, poly-ethylene imine, and poly-l-lysine. From surfactants, 2 phospholipids and 1 anionic surfactant: ammonium salt of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (16:0 PE2000PEG); 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE PEG phospholipids), and sodium dodecylbenzene sulfonate (SDBS) were selected. We analyzed the ability of all passivation agents to screen the non-specific interactions of ssDNA- SWCNTs in the presence of fetal bovine serum using fluorescence spectroscopy. The non-specific interactions between ssDNA-SWCNTs and proteins lead to a reorientation of the dipole moments and charge transfer in the corona phase around ssDNA-SWCNTs, leading to modulation in the center wavelength of the fluorescence as well as absorption peaks. We hence hypothesized that smaller changes in the center wavelength of the fluorescence peaks of passivated ssDNA-SWCNTs in presence of serum, lead to higher screening effect of the passivation agent towards non-specific interactions. We found that the most successful candidates were poly-L-lysine, polyethylene imine, dry-fat milk powder, and casein, in that order. Moreover, the ability to screen the interference was retained over a period of at least 3 hours. We further experimented with the four different mass ratios of passivating agents to ssDNA-SWCNTs and found that the mass ratio 50:1 for passivating agents: ss-DNA SWCNTs was most optimal. We confirmed the strength of passivation using absorption spectroscopy. We hypothesized that stronger surface saturation of the SWCNT-TAT6 is by a passivating agent in buffer conditions leads to a larger shift in the absorption peaks. We found that for the above successful passivation agents, the order of passivation strength followed the same trend as the screening abilities of the successful passivating agents, supporting this mechanistic hypothesis. Then, we evaluated an antibody-conjugated ssDNA-SWCNT nanosensor for the pro-inflammatory cytokine IL-6 with our successful passivation agents. We assessed the ability of the passivation agents to confer selective detection of IL-6 detection in clinical serum samples from patients with atherosclerosis and rheumatoid arthritis, both anticipated to have high IL-6 levels. Samples were compared to healthy human serum sample controls. We validated SWCNT fluorescence response with traditional immunoassays (ELISA). We expect this study to provide rational strategies to screen interferences from non-specific interactions and improve the selectivity of the SWCNT-based optical nanosensors for in vivo applications.

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Sioncke, Sonja, Claudia Fleischmann, Dennis Lin, Evi Vrancken, Matty Caymax, Marc Meuris, Kristiaan Temst, et al. "S-Passivation of the Ge Gate Stack Using (NH₄)₂S." Solid State Phenomena 187 (April 2012): 23–26. http://dx.doi.org/10.4028/www.scientific.net/ssp.187.23.

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The last decennia, a lot of effort has been made to introduce new channel materials in a Si process flow. High mobility materials such as Ge need a good gate stack passivation in order to ensure optimal MOSFET operation. Several routes for passivating the Ge gate stack have been explored in the last years. We present here the S-passivation of the Ge gate stack: (NH4)2S is used to create a S-terminated Ge surface. In this paper the S-treatment is discussed. The S-terminated Ge surface is not chemically passive but can still react with air. After gate oxide deposition, the Ge-S bonds are preserved and an adequate passivation is found for pMOS operation.

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Birant, Gizem, Jorge Mafalda, Romain Scaffidi, Jessica de Wild, Dilara Gokcen Buldu, Thierry Kohl, Guy Brammertz, Marc Meuris, Jef Poortmans, and Bart Vermang. "Rear surface passivation of ultra-thin CIGS solar cells using atomic layer deposited HfOx." EPJ Photovoltaics 11 (2020): 10. http://dx.doi.org/10.1051/epjpv/2020007.

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In this work, hafnium oxide layer is investigated as rear surface passivation layer for ultra-thin (550 nm) CIGS solar cells. Point contact openings in the passivation layer are realized by spin-coating potassium fluoride prior to absorber layer growth. Contacts are formed during absorber layer growth and visualized with scanning electron microscopy (SEM). To assess the passivating qualities, HfOx was applied in a metal-insulator-semiconductor (MIS) structure, and it demonstrates a low interface trap density in combination with a negative density of charges. Since we used ultra-thin devices that are ideal to probe improvements at the rear, solar cell results indicated improvements in all cell parameters by the addition of 2 nm thick HfOx passivation layer with contact openings.

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Rajesh, K., L. J. Huang, W. M. Lau, R. Bruce, S. Ingrey, and D. Landheer. "Modification of the GalnAsP(100) surface by oxidation and sulfur passivation." Canadian Journal of Physics 74, S1 (December 1, 1996): 89–94. http://dx.doi.org/10.1139/p96-839.

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The quaternary III–V compound semiconductor (GaInAsP) is one of the important materials for optoelectronic devices such as long-wavelength semiconductor lasers. Understanding its surface chemistry, which is subjected to oxidation, and sulphur passivation, a widely used passivation technique, is of importance for its use for device fabrication. In this study, modification of the quaternary GaInAsP(100) surfaces was performed by UV/ozone and wet chemical oxidation, dilute HF etching, and sulfur passivation. The surface chemistry and composition of the oxidized, oxide-free, and the sulfur-passivated surfaces were measured by X-ray photoemission spectroscopy (XPS). It was found that oxidation by wet chemical etching resulted in preferential oxidation while, oxidation by ozone exposure formed multiple oxide phases of all the constituent elements. Both the HF etch and sulfur-passivation treatment were effective in generating surfaces having no oxide. Preliminary data on surface Fermi-level changes induced by the above surface treatments indicated that both the HF etch and sulfur-passivation treatment reduced the surface-state density on an oxidized surface.

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Liu, Xiaoliang, Qian Li, Yan Zhang, Yongbin Yang, Bin Xu, and Tao Jiang. "Formation Process of the Passivating Products from Arsenopyrite Bioleaching by Acidithiobacillus ferrooxidans in 9K Culture Medium." Metals 9, no. 12 (December 6, 2019): 1320. http://dx.doi.org/10.3390/met9121320.

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Arsenopyrite is a common sulphide mineral occurring in deposits of gold ore that makes the extraction of gold difficult and, thus, pre-treatment is necessary prior to gold leaching. Bioleaching pre-treatment of arsenopyrite has drawn significant attention owing to its environmental friendliness, low cost and simple operation. A critical impedance of bioleaching to its large-scale industrial application is the slow leaching kinetics. Various passivating products on the surface of arsenopyrite have been found to limit the bioleaching process. This paper reports results from an in-depth investigation into the formation process of passivating products from arsenopyrite bioleaching by Acidithiobacillus ferrooxidans in 9K culture medium including bioleaching experiments and physicochemical analyses of the materials as well as thermodynamic analyses of the leaching system. The results of phase transformation and morphological change of the solid products suggest that the passivation occurring in the bioleaching of arsenopyrite is largely attributed to an initially formed passivating film consisting mainly of realgar (As2S2), orpiment (As2S3) and elemental sulphur (S0) on the arsenopyrite surface. Based on the results, the paper also proposes possible passivation mechanisms to allow for a better understanding on the passivation behaviour of the bioleaching of arsenopyrite.

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Solcansky, M., J. Vanek, and A. Poruba. "Quinhydrone Chemical Passivation of a Silicon Surface for Minority Carrier Bulk-Lifetime Measurements." International Journal of Photoenergy 2012 (2012): 1–4. http://dx.doi.org/10.1155/2012/732647.

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For the measurement of the minority carrier bulk-lifetime the characterization method MW-PCD is used, where the result of measurement is the effective carrier lifetime, which is very dependent on the surface recombination velocity and therefore on the quality of a silicon surface passivation. This work deals with an examination of a different solution types for the chemical passivation of a silicon surface. Various solutions are tested on silicon wafers for their consequent comparison. The main purpose is to find optimal solution, which suits the requirements of a time stability and start-up velocity of passivation, reproducibility of the measurements and a possibility of a perfect cleaning of a passivating solution remains from a silicon surface, so that the parameters of a measured silicon wafer will not worsen and there will not be any contamination of the other wafers series in the production after a repetitive return of the measured wafer into the production process. The cleaning process itself is also a subject of a development.

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Choi, Jea-Young. "Understanding of Molecular Contribution of Quinhydrone/Methanol Organic Passivation for Improved Minority Carrier Lifetime on Nanostructured Silicon Surface." Applied Sciences 9, no. 18 (September 4, 2019): 3645. http://dx.doi.org/10.3390/app9183645.

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In this report, we present a study of the quinhydrone/methanol (QHY/MeOH) organic passivation technique for a silicon (Si) surface. The roles of p-benzoquinone (BQ) and hydroquinone (HQ), which make up QHY, in controlling the uniformity and coverage of the passivation layer as well as the minority carrier lifetime (τeff) of Si were investigated. The uniformity and coverage of the passivation layer after treatment with diverse mixture ratios of BQ and HQ in MeOH were studied with two different atomic force microscope (AFM) techniques, namely tunneling mode (TUNA) and high-resolution tapping mode AFM (HR-AFM). In addition, the τeff and surface potential voltages (SPV) of passivated surfaces were measured to clarify the relationship between the morphologies of the passivation layers and degrees of surface band bending. The molecular interactions between BQ and HQ in MeOH were also analyzed using Fourier-transform infrared spectroscopy (FT-IR). In our study, we successfully demonstrated the role of each molecule for effective Si surface passivation with BQ working as a passivation agent and HQ contributing as a proton (H+) donator to BQ for accelerating the passivation rate. However, our study also clearly revealed that HQ could also hinder the formation of a conformal passivation layer, which raises an issue for passivation over complex surface geometry, especially a nanostructured surface.

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Chowdhury, Sanchari, Muhammad Quddammah Khokhar, Duy Phong Pham, and Junsin Yi. "Al₂O₃/MoO_x Hole-Selective Passivating Contact for Silicon Heterojunction Solar Cell." ECS Journal of Solid State Science and Technology 11, no. 1 (January 1, 2022): 015004. http://dx.doi.org/10.1149/2162-8777/ac4d83.

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Carrier selective contact (CSC) layers have been extensively studied to realize high passivation effect in solar cells. Excellent passivation properties of Al2O3 and a-Si:H(i) as passivating interlayers between the hole-selective contact (HSC) MoOx and p-type c-Si wafer surface are reported herein. MoOx single layer exhibits a high work function value (≥5.0 eV), which can cause sufficient band bending in the band structure for HSC. An Al2O3/MoOx contact exhibits a significantly higher transmittance and surface passivation compared with that of an a-Si:H(i)/MoOx contact. The passivation results for Al2O3/MoOx contact are a carrier lifetime (τeff) of 830 μs and implied open circuit voltage (iVOC) of 726 mV, whereas for conventional a-Si:H(i)/MoOx contact, the corresponding values are 770 μs and 716 mV. Delicate thickness optimization was performed using experimental and simulation results for Al2O3/MoOx and a-Si:H(i)/MoOx stacks to achieve high performance in p-type c-Si solar cells.

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Lebedev M. V., Lvova T. V., Smirnov A. N., Davydov V. Yu., Koroleva A. V., Zhizhin E. V., and Lebedev S. V. "Correlation of the electronic and atomic structure at passivated n-InP(100) surfaces." Semiconductors 56, no. 7 (2022): 477. http://dx.doi.org/10.21883/sc.2022.07.54648.11.

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Photoluminescence, Raman spectroscopy and X-ray photoelectron spectroscopy are used to study electronic and atomic structure of n-InP(100) surfaces treated with different sulfide solutions. It is shown that the sulfide treatment causes removal of the native oxide layer from the semiconductor surface and formation of the passivating layer consisting of In-S chemical bonds with the structure dependent on the solution composition and atomic arrangement at the initial surface of the semiconductor. This is accompanied by an increase in photoluminescence intensity and narrowing of the surface depletion layer. Atomic structure of the passivating layer determines the total dipole that modifies the depth distribution of the bands potentials and thus the surface electronic structure. Keywords: surface modification, sulfur passivation, Raman spectroscopy, photoluminescence, X-ray photoelectron spectroscopy.

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Zhang, Jun, Wei Ming Lu, Chun Lan Zhou, Zhen Li Wen, Lei Zhao, Hai Ling Li, Hong Wei Diao, Yao Zhang, and Wen Jing Wang. "Excellent Surface Passivation by Silicon Dioxide Grown with a Electrochemical Method." Materials Science Forum 685 (June 2011): 48–54. http://dx.doi.org/10.4028/www.scientific.net/msf.685.48.

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A novel method to grow silicon dioxide layers for passivating the silicon surface is given more attention. SiO2was grown by applying a positive voltage across silicon wafers in a nitric acid solution at low temperature. After annealing in N2media at 900°C for 20min, excellent surface passivation was achieved. The maximum effective lifetime of the silicon arrived at 29.8μs and 29.75μs, which was three times the value of silicon without passivation. The effective lifetime of other types of silicon could be ten times the initial value without the silicon dioxide. A comparison study of the effect of the FGA, annealing at low temperature and annealing in N2or O2containing medium at high temperature were investigated.

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Perera, Yasiru Randika, Joanna Xiuzhu Xu, Dhanush L. Amarasekara, Alex C. Hughes, Ibraheem Abbood, and Nicholas C. Fitzkee. "Understanding the Adsorption of Peptides and Proteins onto PEGylated Gold Nanoparticles." Molecules 26, no. 19 (September 24, 2021): 5788. http://dx.doi.org/10.3390/molecules26195788.

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Polyethylene glycol (PEG) surface conjugations are widely employed to render passivating properties to nanoparticles in biological applications. The benefits of surface passivation by PEG are reduced protein adsorption, diminished non-specific interactions, and improvement in pharmacokinetics. However, the limitations of PEG passivation remain an active area of research, and recent examples from the literature demonstrate how PEG passivation can fail. Here, we study the adsorption amount of biomolecules to PEGylated gold nanoparticles (AuNPs), focusing on how different protein properties influence binding. The AuNPs are PEGylated with three different sizes of conjugated PEG chains, and we examine interactions with proteins of different sizes, charges, and surface cysteine content. The experiments are carried out in vitro at physiologically relevant timescales to obtain the adsorption amounts and rates of each biomolecule on AuNP-PEGs of varying compositions. Our findings are relevant in understanding how protein size and the surface cysteine content affect binding, and our work reveals that cysteine residues can dramatically increase adsorption rates on PEGylated AuNPs. Moreover, shorter chain PEG molecules passivate the AuNP surface more effectively against all protein types.

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Ghandi, Reza, Martin Domeij, Romain Esteve, Benedetto Buono, Adolf Schöner, Ji Sheng Han, Sima Dimitrijev, Sergey A. Reshanov, Carl Mikael Zetterling, and Mikael Östling. "Experimental Evaluation of Different Passivation Layers on the Performance of 3kV 4H-SiC BJTs." Materials Science Forum 645-648 (April 2010): 661–64. http://dx.doi.org/10.4028/www.scientific.net/msf.645-648.661.

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In this work, the electrical performance in terms of maximum current gain, ON-resistance and blocking capability has been compared for 4H-SiC BJTs passivated with different surface passivation layers. Variation in BJT performance has been correlated to densities of interface traps and fixed oxide charge, as evaluated through MOS capacitors. Six different methods were used to fabricate SiO2 surface passivation on BJT samples from the same wafer. The highest current gain was obtained for PECVD deposited SiO2 which was annealed in N2O ambient at 1100 °C during 3 hours. Variations in breakdown voltage for different surface passivations were also found, and this is attributed to differences in fixed oxide charge that can affect the optimum dose of the high voltage JTE termination.

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Barek, Jiri. "How to Improve the Performance of Electrochemical Sensors via Minimization of Electrode Passivation." Chemosensors 9, no. 1 (January 6, 2021): 12. http://dx.doi.org/10.3390/chemosensors9010012.

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It follows from critical evaluation of possibilities and limitations of modern voltammetric/amperometric methods that one of the biggest obstacles in their practical applications in real sample analysis is connected with electrode passivation/fouling by electrode reaction products and/or matrix components. This review summarizes possibilities how to minimise these problems in the field of detection of small organic molecules and critically compares their potential and acceptability in practical laboratories. Attention is focused on simple and fast electrode surface renewal, the use of disposable electrodes just for one and/or few measurements, surface modification minimising electrode fouling, measuring in flowing systems, application of rotating disc electrode, the use of novel separation methods preventing access of passivating particles to electrode surface and the novel electrode materials more resistant toward passivation. An attempt is made to predict further development in this field and to stress the need for more systematic and less random research resulting in new measuring protocols less amenable to complications connected with electrode passivation.

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Xiang, Yu Ren, Chun Lan Zhou, and Wen Jing Wang. "The Effect of Substrate Surface Condition on Atomic Layer Deposited Alumina Passivation Films." Key Engineering Materials 703 (August 2016): 230–34. http://dx.doi.org/10.4028/www.scientific.net/kem.703.230.

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Aluminum oxide (Al2O3) films have been wildly investigated due to the excellent surface passivation for the electrical device. Both hydrogen-terminated and pre-oxidized silicon surfaces were prepared before Al2O3 films deposition. Combining chemical environment analysis with the effective minority lifetime data, the effect of the surface conditions on the Al2O3 films passivation was discussed. The HF sample with hydrogen-terminated substrate surface had a higher minority carrier lifetime (about 721 μs) than the H2SO4+H2O2 sample with pre-oxidized substrate surface (about 631 μs). The H atoms played an important role in improving the passivation effect. And the importance of the interfacial oxide layer to Al2O3 films passivation was validated too.

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Lee, H. H., R. J. Racicot, and S. H. Lee. "Surface passivation of GaAs." Applied Physics Letters 54, no. 8 (February 20, 1989): 724–26. http://dx.doi.org/10.1063/1.100873.

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Кукушкин, С. А., И. П. Калинкин, and А. В. Осипов. "Влияние химической подготовки поверхности кремния на качество и структуру эпитаксиальных пленок карбида кремния, синтезированных методом замещения атомов." Физика и техника полупроводников 52, no. 6 (2018): 656. http://dx.doi.org/10.21883/ftp.2018.06.45932.8758.

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AbstractThe fundamentals of a new technique for the cleaning and passivation of (111), (110), and (100) silicon wafer surfaces by hydride groups, which ensure a high surface purity and smoothness at the nanoscale upon long-term storage of the wafers at room temperature in air, are discussed. A new composition of the passivation solution for the long-term antioxidation protection of silicon surfaces is developed. The proposed solution is suitable for the long-term storage and repeated passivation of silicon wafers. The composition of the passivation solution and the conditions of passivation of the silicon wafers in it are described. Silicon wafers treated using the proposed technique can be used for growing epitaxial semiconductor films and different nanostructures. It is shown that only silicon surfaces prepared in this way allow SiC epitaxial films on silicon to be grown by atom substitution. The experimental dependences of the SiC and GaN film structures grown on silicon on the silicon-surface etching conditions are presented. The developed technique for silicon cleaning and passivation can both be used under laboratory conditions and easily adapted for the industrial production of silicon wafers with an oxidation-resistant surface coating.

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Abbas, Mahmoud, M. A. Shahin, Mohamed M. I. Ahmed, and Magdy Kasem. "Passivation of Recirculating Open Water Cooling Systems Using New Organic Passivator." Journal of University of Shanghai for Science and Technology 23, no. 12 (December 22, 2021): 375–86. http://dx.doi.org/10.51201/jusst/21/121028.

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It is well know that recirculating open cooling water system at metal/ water surface contact appear frequent corrosion products, like scales, foaling and material losses which are have great effect on cooling process. Passivation helps to maintain clean heat transfer surface by inhibiting oxides scales through creating outer passive layer. Passivators are substances which usually have a sufficiently high equilibrium potential and sufficiently low over potential decrease corrosion rate on attainment of passivity. One of the most popular passivator is organic phosphate Phosphinosuccinic oligomer C15H14O4P component (PSO) The study of passivation of carbon steel pipe line in recirculating open cooling water system was the aim of this present work. Maximum efficiency of passivator was determined and surface morphology were investigated using optical, scanning microscopy, phase analysis of the formed protective layer was exam by XRD and EDX. Corrosion in running water with and without PSO at 2 m3/hr flow rate was investigated using corrosion coupon rack. It was found that 200 ppm (PSO) decreases corrosion rate of carbon steel pipe in 3.5% NaCL solution from 23 to 7 mpy in stagnate water corrosion testing, while in running water in 3.5% NaCL solution it decreases from 45 to 18 mpy. XDR showed that the protective layer due to passivation is mainly Magnetite (Fe3O4) compound.

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Zhao, Yang, Yuchen Liu, Xin Gai, Yun Bai, Tao Zhang, Dake Xu, and Fuhui Wang. "Investigating the Stress Corrosion Cracking (SCC) Susceptibility of Ti-6Al-4V Alloys Fabricated by Electron Beam Melting in Deep-Sea Environment." Corrosion 77, no. 8 (May 11, 2021): 853–65. http://dx.doi.org/10.5006/3822.

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The stress corrosion cracking (SCC) susceptibility of electron beam melted Ti-6Al-4V alloy (ET) was compared with the conventional wrought alloy (WT). The electrochemical and slow strain rate tensile (SSRT) tests, as well as surface analysis, were conducted under simulated shallow and deep-sea environment. Under shallow conditions, the SCC susceptibility of both alloys was almost the same because of consistent passivation and repassivation performance of the passivating film. However, under deep-sea conditions, SCC susceptibility of ET was higher than that of WT due to stronger textured-like surface that appeared on ET alloy, where early developed passive film broke down, demonstrating lower passivation and repassivation rate.

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Shi, Jingying, Xuefei Zhao, and Can Li. "Surface Passivation Engineering for Photoelectrochemical Water Splitting." Catalysts 13, no. 2 (January 17, 2023): 217. http://dx.doi.org/10.3390/catal13020217.

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Surface passivation engineering is an imperative way to improve photoelectrode performance for photoelectrochemical (PEC) water splitting. To the best of our knowledge, it has never been systematically reviewed in a feature article. In this review, we summarize various passivation materials and their preparation, characterizations by PEC measurements and some related spectral technologies. We highlight the features of the passivation effect that separate it from other modifications, such as cocatalyst decoration, and we demonstrate significant progress in combining surface passivation engineering with other interfacial modification strategies for the rational design of photoelectrodes. Ideas for future research on surface passivation modification for improving the performance of photoelectrodes are also proposed.

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Cuevas, Jose Luis, Miguel Ojeda Martinez, and Saravana Prakash Thirumuruganandham. "Band-Gap Engineering: Lithium Effect on the Electronic Properties of Hydrogenated 3C-SiC (1 1 0) Surfaces." Batteries 8, no. 11 (November 18, 2022): 247. http://dx.doi.org/10.3390/batteries8110247.

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Silicon carbide has structural strength, high electronic conductivity, low diffusion barrier and high storage capacity, which are suitable for engineering applications such as lithium-ion batteries, electric vehicles, uninterruptible power supplies and SiC diodes. In particular, 3C-SiC monolayers oriented along the (1 1 0) crystallographic direction that could have symmetric surfaces have been poorly studied, as have the effects of surface passivation on their physical and electronic properties. In this work, we investigate the influence of lithium on the electronic properties of hydrogenated surfaces in 3C-SiC monolayers using density functional theory. We examine the electronic properties of surfaces fully passivated with hydrogen with those of surfaces fully passivated with lithium and those with mixed passivation. Our results show that only fully hydrogenated surfaces exhibit a direct band-gap, while the full Li, CH+SiLi, and H+Lic passivations exhibit metallic behavior. The CLi+SiH, H+1LiC, and H+1LiSi passivation systems decrease the band-gap compared to the hydrogenated case and show an indirect band-gap. The formation energy of the system shows that the most stable arrangement is full-H, followed by H+1LiC, and the most unstable system is full-Li, which has a positive formation energy.

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Palais, Olivier, Mustapha Lemiti, Jean-Francois Lelievre, and Santo Martinuzzi. "Comparison of Efficiencies of Different Surface Passivations Applied to Crystalline Silicon." Solid State Phenomena 108-109 (December 2005): 585–90. http://dx.doi.org/10.4028/www.scientific.net/ssp.108-109.585.

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In this work the efficiencies of different surface passivation techniques are compared. This paper emphasizes on the passivation provided by SiNx:H layers that is commonly used in photovolaic industry as surface passivation and anti reflection layer. The method used to evaluate the surface recombination velocity is detailed and discussed. It is shown that light phosphorus diffusion at 850°C – 20 min provides good surface passivation of n-type silicon surface and noticeable passivation of p-type, that can be improved by SiNx:H Layer.

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Lu, Haizhou, Huotian Zhang, Sijian Yuan, Jiao Wang, Yiqiang Zhan, and Lirong Zheng. "An optical dynamic study of MAPbBr3 single crystals passivated with MAPbCl3/I3-MAPbBr3 heterojunctions." Physical Chemistry Chemical Physics 19, no. 6 (2017): 4516–21. http://dx.doi.org/10.1039/c6cp07182a.

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Sundarapura, Panus, Xiao-Mei Zhang, Ryoji Yogai, Kazuki Murakami, Alain Fave, and Manabu Ihara. "Nanostructure of Porous Si and Anodic SiO2 Surface Passivation for Improved Efficiency Porous Si Solar Cells." Nanomaterials 11, no. 2 (February 11, 2021): 459. http://dx.doi.org/10.3390/nano11020459.

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The photovoltaic effect in the anodic formation of silicon dioxide (SiO2) on porous silicon (PS) surfaces was investigated toward developing a potential passivation technique to achieve high efficiency nanostructured Si solar cells. The PS layers were prepared by electrochemical anodization in hydrofluoric acid (HF) containing electrolyte. An anodic SiO2 layer was formed on the PS surface via a bottom-up anodization mechanism in HCl/H2O solution at room temperature. The thickness of the oxide layer for surface passivation was precisely controlled by adjusting the anodizing current density and the passivation time, for optimal oxidation on the PS layer while maintaining its original nanostructure. HRTEM characterization of the microstructure of the PS layer confirms an atomic lattice matching at the PS/Si interface. The dependence of photovoltaic performance, series resistance, and shunt resistance on passivation time was examined. Due to sufficient passivation on the PS surface, a sample with anodization duration of 30 s achieved the best conversion efficiency of 10.7%. The external quantum efficiency (EQE) and internal quantum efficiency (IQE) indicate a significant decrease in reflectivity due to the PS anti-reflection property and indicate superior performance due to SiO2 surface passivation. In conclusion, the surface of PS solar cells could be successfully passivated by electrochemical anodization.

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Cruz, Nuno, Javier Gil, Miquel Punset, José María Manero, João Paulo Tondela, Pablo Verdeguer, Conrado Aparicio, and Elisa Rúperez. "Relevant Aspects of Piranha Passivation in Ti6Al4V Alloy Dental Meshes." Coatings 12, no. 2 (January 27, 2022): 154. http://dx.doi.org/10.3390/coatings12020154.

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Passivation of titanium alloy dental meshes cleans their surface and forms a thin layer of protective oxide (TiO2) on the surface of the material to improve resistance to corrosion and prevent release of ions to the physiological environment. The most common chemical agent for the passivation process of titanium meshes is hydrochloric acid (HCl). In this work, we introduce the use of Piranha solution (H2SO4 and H2O2) as a passivating and bactericidal agent for metallic dental meshes. Meshes of grade 5 titanium alloy (Ti6Al4V) were tested after different treatments: as-received control (Ctr), passivated by HCl, and passivated by Piranha solution. Physical-chemical characterization of all treated surfaces was carried out by scanning electron microscopy (SEM), confocal microscopy and sessile drop goniometry to assess meshes’ topography, elemental composition, roughness, wettability and surface free energy, that is, relevant properties with potential effects for the biological response of the material. Moreover, open circuit potential and potentiodynamic tests were carried out to evaluate the corrosion behavior of the differently-treated meshes under physiological conditions. Ion release tests were conducted using Inductively Coupled Plasma mass spectrometry (ICP-MS). The antibacterial activity by prevention of bacterial adhesion tests on the meshes was performed for two different bacterial strains, Pseudomonas aeruginosa (Gram-) and Streptococcus sanguinis (Gram+). Additionally, a bacterial viability study was performed with the LIVE/DEAD test. We complemented the antibacterial study by counting cells attached to the surface of the meshes visualized by SEM. Our results showed that the passivation of titanium meshes with Piranha solution improved their hydrophilicity and conferred a notably higher bactericidal activity in comparison with the meshes passivated with HCl. This unique response can be attributed to differences in the obtained nanotextures of the TiO2 layer. However, Piranha solution treatment decreased electrochemical stability and increased ion release as a result of the porous coating formed on the treated surfaces, which can compromise their corrosion resistance. Framed by the limitations of this work, we conclude that using Piranha solution is a viable alternative method for passivating titanium dental meshes with beneficial antibacterial properties that merits further validation for its translation as a treatment applied to clinically-used meshes.

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Anas, Muhammad Mus-'ab, and Geri Gopir. "Surface Passivation Effect of Hydrogen and Methyl on the Structural and Electronic Properties of Silicon Quantum Dots: Density Functional Calculation." Materials Science Forum 846 (March 2016): 375–82. http://dx.doi.org/10.4028/www.scientific.net/msf.846.375.

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We have carried out a series of DFT calculations to investigate changes on the structural and electronic properties of Silicon (Si) quantum dots as a function of surface passivation. In particular, we have study non-polar passivation effect of hydrogen (H) and methyl (CH3) at the surface of quantum dots. From geometry optimization result, we find that clusters with reconstructed surfaces a complete methyl passivation is possible and steric repulsion prevents full passivation of Si dots with unreconstructed surfaces. On the electronic properties point of view, it is noticed for small nanocrystals, the presence of mini-gaps are more pronounced which can limit the non-radiative relaxation of excitons. Obviously, methyl passivation weakly affects the band gap values of silicon quantum dots, while it substantially decreases the band gap and reduce mini-gap appearance compared to hydrogen passivation Si QDs. On the basis of our results we propose that methyl terminated quantum dots may be size selected taking advantage of the reduction on mini-gap and the localization of electron as a function of the cluster size.

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Jha, Rajesh Kumar, Prashant Singh, Manish Goswami, and B. R. Singh. "Impact of HfO2 as a Passivation Layer in the Solar Cell Efficiency Enhancement in Passivated Emitter Rear Cell Type." Journal of Nanoscience and Nanotechnology 20, no. 6 (June 1, 2020): 3718–23. http://dx.doi.org/10.1166/jnn.2020.17510.

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We report the simulation of high-efficiency c-silicon Passivated Emitter Rear Contact (PERC) type solar cell structure with rear side passivated with HfO2 as a passivating material. Variation in the half length of pyramid has been carried out to investigate its effect on the solar cell electrical characteristics such as fill factor (FF), open circuit voltage (Voc) and efficiency. Aluminum back Surface Field (Al-BSF) and PERC type solar cell with Al2O3 passivation layer structures were also modeled for comparison. Effect of variation in passivation layer (HfO2) thickness (10 and 15 nm) and permittivity (k = 14 and 25) on the solar cell electrical characteristics has been investigated. Result shows the efficiency improvement in the PERC solar cell with HfO2 passivation layer by 0.5941% and 0.983% as compared to the Al-BSF and PERC with Al2O3 passivation layer at 8 μm pyramid half length. Increased series resistance and reduced FF has been observed with the incorporation of passivation layer at the solar cell structure. Negligible effect of passivation layer thickness has been observed on the solar cell electrical parameters whereas the permittivity value does have significant effect.

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Cao, Fan, Peng Cao, Yangyang Li, Yi Wang, Lei Shi, and Di Wu. "Inhibition of Surface Corrosion Behavior of Zinc-Iron Alloy by Silicate Passivation." Coatings 13, no. 6 (June 7, 2023): 1057. http://dx.doi.org/10.3390/coatings13061057.

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The passivation of zinc alloy coating was achieved through the utilization of both silicate and trivalent chromium passivation systems, employing a specific process formula consisting of Co(NO3)2 at a concentration of 2.5 g/L, C76H52O46 at 3 mL/L, Na2SiO3 at 25 g/L, C6H5Na3O7 at 15 g/L, and an appropriate amount of organic accelerator. The composite passivation of silicate and tannic acid was found to be more effective than the trivalent chromium passivation film, as it successfully eliminated the dendrite structure on the coating surface and reduced surface defects. The coordination between negatively charged SiO2− or SiO2 micelles and Zn2+ results in the formation of a passivation film that exhibits lower corrosion current and higher corrosion potential compared to the trivalent chromium passivation film. Additionally, the impedance test fitting results indicate that the silicate passivation film possesses a higher resistance value. Overall, the proposed silicate passivation system presents a viable alternative to the toxic chromate passivation system, offering non-toxicity and superior protective performance relative to the trivalent chromium passivation system.

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Ghoshal, Sib Krishna, M. R. Sahar, R. Arifin, M. S. Rohani, and K. Hamzah. "Surface States and Band Gap Correlation in Silicon Nanoclusters." Advanced Materials Research 1107 (June 2015): 308–13. http://dx.doi.org/10.4028/www.scientific.net/amr.1107.308.

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Tuning the visible emission of Si nanomaterials by modifying their size and shape is one of the key issue in optoelectronics. The observed optical gain in Si-nanoclusters (NCs) has given further impulse to nanosilicon research. We develop a phenomenological model by combining the effects of surface passivation, exciton states and quantum confinement (QC). The size and passivation dependent band gap, oscillator strength, radiative lifetime and photoluminescence (PL) intensity for NCs with diameter ranging from 1.0 to 6.0 nm are presented. By controlling a set of fitting parameters, it is possible to tune the optical band gap, PL peak and intensity. In case of pure clusters, the band gap is found to decrease with increasing NC size. Furthermore, the band gap increases on passivating the surface of the cluster with hydrogen and oxygen respectively in which the effect of oxygen is more robust. Both QC and surface passivation in addition to exciton effects determine the optical and electronic properties of silicon NCs. Visible luminescence is due to radiative recombination of electrons and holes in the quantum-confined NCs. The role of surface states on the band gap as well as on the HOMO-LUMO states is also examined and a correlation is established. Our results are in conformity with other observations. The model can be extended to study the light emission from other nanostructures and may contribute towards the development of Si based optoelectronics.

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Niikura, Chisato, Yuta Shiratori, and Shinsuke Miyajima. "Si surface passivation by using triode-type plasma-enhanced chemical vapor deposition with thermally energized film-precursors." European Physical Journal Applied Physics 89, no. 1 (January 2020): 10101. http://dx.doi.org/10.1051/epjap/2020190299.

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We fabricated hydrogenated amorphous Si (a-Si:H) passivation layers on the surfaces of Si wafers by using triode-type plasma-enhanced chemical vapor deposition with gas-heating, and discussed high-quality surface passivation for Si heterojunction solar cells. The sample with the a-Si:H layers corresponding to the highest proportion of SiHx(x=2,3) content in SiHx(x=1–3) content exhibited the minimum surface recombination velocity (S) after annealing. This suggests that using SiHx(x=2,3)-rich a-Si:H grown at low-temperature as a passivation layer is advantageous to inhibit an epitaxial growth at the a-Si:H/crystalline Si interface, and that a structural relaxation of the a-Si:H takes place during post-deposition annealing, drastically improving passivation quality. Also, the importance to use a low Tsub and to optimize gas-heating and the triode technique, for obtaining simultaneously higher film quality and abrupt interface, is suggested. Low S obtained for our unoptimized samples implies the potency of this deposition technique. Nevertheless, further studies are needed to elucidate the impact of gas-heating and the triode technique on Si surface passivation. Temperature-dependent effective carrier lifetime for our samples might suggest relatively large electron affinity for an a-Si:H, which might be one possible reason for high-quality surface passivation.

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Mathew, Varughese, Sheila Chopin, Trent Uehling, and Ruzaini Ibrahim. "Mold Compound Adhesion Reliability with SiN and SiON Passivation." International Symposium on Microelectronics 2011, no. 1 (January 1, 2011): 000729–34. http://dx.doi.org/10.4071/isom-2011-wp2-paper6.

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Delamination of mold compounds under thermal stress conditions such as Air-to-Air Temperature Cycling (AATC) (−55°C −125° C) was studied for two passivation surfaces; SiN and SiON using C-Mode Scanning Acoustic Microscope (CSAM) and electrical testing for different intervals up to 2000 cycles. Both passivation surfaces were treated with oxygen-argon plasma prior to the molding process. It is found that SiN surface performed better than SiON electrically and without showing any delamination for the mold compound studied. Both passivation surfaces were analyzed for various surface groups by TOF-SIMS analysis immediately before and after the pre-mold plasma treatment process. Different surface groups such as CH, NH etc. were identified, but the major difference was found in the OH intensity. Fraction of OH is significantly increased after plasma treatment for SiN surface while it is decreased for SiON surface. It is inferred that OH group can play a role in enhancing the mold compoundpassivation adhesion and hence provide better delamiantion resistance.

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Guilherme, Luis Henrique, Cecilio Sadao Fugivara, and Assis Vicente Benedetti. "On-site weld quality assessment and qualification for stainless steels tanks." Ecl�tica Qu�mica Journal 47, no. 3 (July 1, 2022): 55–65. http://dx.doi.org/10.26850/1678-4618eqj.v47.3.2022.p55-65.

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Stainless steel tanks are frequently degraded by localized corrosion in bioprocess industries. A case study of 2101 duplex stainless steel tank allowed to apply a portable electrochemical microcell system (PassivityScan) for on-site weld inspection and corrosion monitoring from the manufacturing until 12 months of operation. During the tank manufacturing, the double loop electrochemical potentiokinetic reactivation technique was applied to measure the sensitization degree on the welded regions. The manufactured tank was submitted to the passivation treatment to improve the passivation properties and corrosion resistance. On-site cyclic polarization tests were performed and confirmed the increase of passivation level of treated surface. The passivation level was measured again after 12�months of operation and detected a lower passivation level compared to the initial passivated surface, indicating that the passivation treatment lost its effect after that period. Therefore, an acceptance criterion to passivation level was empirically determined. PassivityScan is an advanced device to qualify the welds and the passivated surfaces, and useful for corrosion monitoring and the reliability maintenance.

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Kim, Joo-Wan, Tae-Wan Kim, Sungjune Lee, Nanah Kim, Kwang-Eun Jeong, Soon-Young Jeong, and Chul-Ung Kim. "Effects of Steaming and SiO2 Surface Passivation on SSZ-13 Zeolites in the Ethylene to Propylene Reaction." Journal of Nanoscience and Nanotechnology 20, no. 9 (September 1, 2020): 5783–86. http://dx.doi.org/10.1166/jnn.2020.17644.

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SSZ-13 zeolite was modified by two kinds of post-treatment methods such as steaming and SiO2 surface passivation (silylation) for ETP catalyst with high activity. The former steaming treatment was conducted in the range of 400–700 °C, whereas the latter surfaces passivation was applied to a chemical liquid deposition (CLD) technique that uses various silylation agents such as tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), and tetrabuthylorthosilicate (TBOS). Catalysts were characterized by powder-XRD, ICP, Ar-phsisorption, solid-state 27Al MAS NMR, and NH3-TPD, and their activities were tested in fixed bed reaction system. Regarding the effects of steaming temperature, the results show that a relatively higher selectivity is observed in SSZ-13 catalysts treated at proper steaming temperatures such as 450 and 500 °C compared to parent and other steam treated catalysts. For optimum surface passivation treatments for ETP reactions, one-step surface passivation using TEOS agents among various passivation agents led to enhanced propylene selectivity to 80% when compared with parent and other silylated SSZ-13 catalysts. However, a sequential passivation treatment with a TEOS agent was not highly affected by the reaction activity.

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McBrayer, Josefine, Katharine L. Harrison, Kyle Fenton, and Shelley Minteer. "SECM as a Direct Method to Track Changes in Silicon Passivation." ECS Meeting Abstracts MA2023-01, no. 2 (August 28, 2023): 514. http://dx.doi.org/10.1149/ma2023-012514mtgabs.

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Silicon is a promising next-generation anode to increase energy density over current state of the art graphite anodes. Despite much progress in improving the cycling of silicon electrodes, the calendar life is still problematic. In this work, scanning electrochemical microscopy (SECM) was used to track the reactivity of the surface of a silicon thin film over time to better understand the role of the solid electrolyte interphase (SEI) during calendar aging. The passivation of silicon was found to decrease with increasing time and potential relative to Li/Li+. Along with the decrease in passivation with time, the homogeneity of passivation decreases. Despite some local “hot spots” of reactivity, within resolution limits (tip radius of 12.5 μm), the changes in passivation seemed to be global SEI failure rather than local (for example, cracking). In all cases, the delithiated silicon was less passivated than the lithiated silicon. When delithiated up to 1.5 V versus Li/Li+ the surface was found to be more reactive than the pristine silicon surface. This could potentially be the result of destabilization of the surface by SEI oxidation. When the cell was only delithiated up to 0.75 V versus Li/Li+, the surface was still passivating, but still less so than the lithiated surface. This indicates that the potential of the anode should be kept at or below ∼ 0.75 V Li/Li+ for half cell and full cell cycling to prevent decreasing SEI passivation. This research was supported by the U.S. Department of Energy’s Vehicle Technologies Office under the Silicon Consortium Project, directed by Brian Cunningham, and managed by Anthony Burrell. This work was conducted in part by the Alliance for Sustainable Energy, LLC, the manager and operator of the National Renewable Energy Laboratory for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Sandia National Laboratories is a multimission Laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

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Hyun, Ji Yeon, Soohyun Bae, Yoon Chung Nam, Dongkyun Kang, Sang-Won Lee, Donghwan Kim, Jooyoung Park, Yoonmook Kang, and Hae-Seok Lee. "Surface Passivation of Boron Emitters on n-Type Silicon Solar Cells." Sustainability 11, no. 14 (July 10, 2019): 3784. http://dx.doi.org/10.3390/su11143784.

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Al2O3/SiNx stack passivation layers are among the most popular layers used for commercial silicon solar cells. In particular, aluminum oxide has a high negative charge, while the SiNx film is known to supply hydrogen as well as impart antireflective properties. Although there are many experimental results that show that the passivation characteristics are lowered by using the stack passivation layer, the cause of the passivation is not yet understood. In this study, we investigated the passivation characteristics of Al2O3/SiNx stack layers. To identify the hydrogenation effect, we analyzed the hydrogen migration with atom probe tomography by comparing the pre-annealing and post-annealing treatments. For chemical passivation, capacitance-voltage measurements were used to confirm the negative fixed charge density due to heat treatment. Moreover, the field-effect passivation was understood by confirming changes in the Al2O3 structure using electron energy-loss spectroscopy.

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Calvino, M., A. Trejo, M. I. Iturrios, M. C. Crisóstomo, Eliel Carvajal, and M. Cruz-Irisson. "DFT Study of the Electronic Structure of Cubic-SiC Nanopores with a C-Terminated Surface." Journal of Nanomaterials 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/471351.

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A study of the dependence of the electronic structure and energetic stability on the chemical surface passivation of cubic porous silicon carbide (pSiC) was performed using density functional theory (DFT) and the supercell technique. The pores were modeled by removing atoms in the [001] direction to produce a surface chemistry composed of only carbon atoms (C-phase). Changes in the electronic states of the porous structures were studied by using different passivation schemes: one with hydrogen (H) atoms and the others gradually replacing pairs of H atoms with oxygen (O) atoms, fluorine (F) atoms, and hydroxide (OH) radicals. The results indicate that the band gap behavior of the C-phase pSiC depends on the number of passivation agents (other than H) per supercell. The band gap decreased with an increasing number of F, O, or OH radical groups. Furthermore, the influence of the passivation of the pSiC on its surface relaxation and the differences in such parameters as bond lengths, bond angles, and cell volume are compared between all surfaces. The results indicate the possibility of nanostructure band gap engineering based on SiC via surface passivation agents.

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Hu, Xiaochen, Pei Zhang, Yong Zhou, and Fuan Yan. "The electrochemical behavior of corrosion and passivation for Q235 carbon steel in acidic phosphate buffer solutions without and with NO2−." Anti-Corrosion Methods and Materials 67, no. 5 (August 5, 2020): 473–81. http://dx.doi.org/10.1108/acmm-03-2020-2285.

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Purpose The purpose of this paper is to reveal the mechanism of nitrite (NO2−) for the surface passivation of carbon steels in acidic environments through investigating the influences of 0.01 mol/L NaNO2 addition on the corrosion and passivation behaviors of Q235 carbon steel in acidic phosphate buffer (APB) solutions (pH 2 to 6). Design/methodology/approach The electrochemical techniques including open circle potential evolution, potentiodynamic polarization, electrochemical impedance spectroscopy and cyclic voltammetry were applied. Findings In APB solutions without NO2−, the Q235 steel presented the electrochemical behaviors of activation (A), activation-passivation-transpassivation and self-passivation-transpassivation at pH 2 to 4, pH 5 and pH 6, respectively; the corrosion rate decreased with the up of pH value, and the surface passivation occurred in the pH 5 and pH 6 solutions only: the anodic passivation at pH 5 and the spontaneous passivation at pH 6. Originality/value In APB solutions without NO2−, the corrosion rate decreased with the up of pH value, and the surface passivation occurred in the pH 5 and pH 6 solutions only: the anodic passivation at pH 5 and the spontaneous passivation at pH 6. With the addition of 0.01 mol/L NaNO2, into APB solutions, the variation of corrosion rate showed the same rule, but the surface passivation occurred over the whole acidic pH range, including the anodic passivation at pH 2 to 4 and the spontaneous passivation at pH 5 to 6.

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Lee, C. H., Z. D. Lin, N. G. Shang, L. S. Liao, I. Bello, N. Wang, and S. T. Lee. "Surface passivation in diamond nucleation." Physical Review B 62, no. 24 (December 15, 2000): 17134–37. http://dx.doi.org/10.1103/physrevb.62.17134.

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Charache, G. W., S. Akram, E. W. Maby, and I. B. Bhat. "Surface passivation of GaAs MESFETs." IEEE Transactions on Electron Devices 44, no. 11 (1997): 1837–42. http://dx.doi.org/10.1109/16.641350.

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Zimmermann, P. H., M. B. Reine, K. Spignese, K. Maschhoff, and J. Schirripa. "Surface passivation of HgCdTe photodiodes." Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 8, no. 2 (March 1990): 1182–84. http://dx.doi.org/10.1116/1.576941.

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Reese, M. O., C. L. Perkins, J. M. Burst, S. Farrell, T. M. Barnes, S. W. Johnston, D. Kuciauskas, T. A. Gessert, and W. K. Metzger. "Intrinsic surface passivation of CdTe." Journal of Applied Physics 118, no. 15 (October 21, 2015): 155305. http://dx.doi.org/10.1063/1.4933186.

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Xiaoqin, Wang, Jie Wanqi, Li Qiang, and Gu Zhi. "Surface passivation of CdZnTe wafers." Materials Science in Semiconductor Processing 8, no. 6 (January 2005): 615–21. http://dx.doi.org/10.1016/j.mssp.2005.11.001.

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Vera, Andrés Manuel, and Philip Tinnefeld. "Single-Molecule Approved Surface Passivation." Structure 28, no. 12 (December 2020): 1269–70. http://dx.doi.org/10.1016/j.str.2020.11.009.

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Journal articles on the topic 'Surface passivation'

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