Journal articles: 'Wide bandgap device'

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Anderson, Travis J., Jennifer K. Hite, and Fan Ren. "Ultra-Wide Bandgap Materials and Device." ECS Journal of Solid State Science and Technology 6, no. 2 (2017): Y1. http://dx.doi.org/10.1149/2.0151702jss.

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Firdaus, Yuliar, Qiao He, Lia Muliani, Erlyta Septa Rosa, Martin Heeney, and Thomas D. Anthopoulos. "Charge transport and recombination in wide-bandgap Y6 derivatives-based organic solar cells." Advances in Natural Sciences: Nanoscience and Nanotechnology 13, no. 2 (May 11, 2022): 025001. http://dx.doi.org/10.1088/2043-6262/ac6c23.

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Abstract The power conversion efficiency of nonfullerene-based organic solar cells (OSCs) has recently exceeded 18%, thanks to the constant effort to identify the key properties governing the OSCs performance and development of better photovoltaic materials. With its superior properties, low-bandgap Y6 and its derivatives have emerged as one of the most popular nonfullerene acceptors (NFAs) for OSCs. In most cases, these low bandgap NFAs were based mainly on the most widely used and successful end-group 1,1-dicyanomethylene-3-indanone (IC). On the other hand, wide-bandgap Y6 derivatives are still scarce. Attempts to increase the NFA’s bandgap by incorporating electron-rich end-groups often end up with NFAs with poor performance. In this work, we compare two wide-bandgap Y6 derivatives with different end-groups, and their distinct device performance is correlated with their charge transport and recombination properties. Electronic measurements on solar cell devices and device physics results are presented to discuss charge transport and recombination within the device.

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Sugimoto, M., H. Ueda, T. Uesugi, and T. kachi. "WIDE-BANDGAP SEMICONDUCTOR DEVICES FOR AUTOMOTIVE APPLICATIONS." International Journal of High Speed Electronics and Systems 17, no. 01 (March 2007): 3–9. http://dx.doi.org/10.1142/s012915640700414x.

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In this paper, we discuss requirements of power devices for automotive applications, especially hybrid vehicles and the development of GaN power devices at Toyota. We fabricated AlGaN/GaN HEMTs and measured their characteristics. The maximum breakdown voltage was over 600V. The drain current with a gate width of 31mm was over 8A. A thermograph image of the HEMT under high current operation shows the AlGaN/GaN HEMT operated at more than 300°C. And we confirmed the operation of a vertical GaN device. All the results of the GaN HEMTs are really promising to realize high performance and small size inverters for future automobiles.

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Kumar, Ashwani, Sheetal Singh, and Divyanshu Shukla. "Preparation Properties and Device Application of ?- Ga2O3: A Review." International Journal for Research in Applied Science and Engineering Technology 10, no. 8 (August 31, 2022): 360–74. http://dx.doi.org/10.22214/ijraset.2022.46195.

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Abstract: Extremely wide-bandgap β-Ga2O3 is a new way semiconducting has wide range of application such as electronics devices operated at high temperature and short-wavelength optoelectronics. It has a wide bandgap of 4.5eV -4.9 electron volt (ev) and great thermal stabilization up to 14000C, opening new possibilities for various device applications. The development of βGa2O3 thin film growth, characteristics, and device demonstrations is reviewed in this study. The methods used to demonstrate great-quality β-Ga2O3 thin film growth with controlled doping are discussed. Monoclinic β-Ga2O3 applications in devices are also discussed. Finally, a conclusion will be offered and future research perspectives on this key semiconducting material.

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Kumar, Ashwani, Sheetal Singh, and Divyanshu Shukla. "Preparation Properties and Device Application of ?- Ga2O3: A Review." International Journal for Research in Applied Science and Engineering Technology 10, no. 8 (August 31, 2022): 360–74. http://dx.doi.org/10.22214/ijraset.2022.46195.

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Abstract: Extremely wide-bandgap β-Ga2O3 is a new way semiconducting has wide range of application such as electronics devices operated at high temperature and short-wavelength optoelectronics. It has a wide bandgap of 4.5eV -4.9 electron volt (ev) and great thermal stabilization up to 14000C, opening new possibilities for various device applications. The development of βGa2O3 thin film growth, characteristics, and device demonstrations is reviewed in this study. The methods used to demonstrate great-quality β-Ga2O3 thin film growth with controlled doping are discussed. Monoclinic β-Ga2O3 applications in devices are also discussed. Finally, a conclusion will be offered and future research perspectives on this key semiconducting material.

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Liyanage, Geethika K., Adam B. Phillips, Fadhil K. Alfadhili, and Michael J. Heben. "Numerical Modelling of Front Contact Alignment for High Efficiency Cd1-xZnxTe and Cd1-xMgxTe Solar Cells for Tandem Devices." MRS Advances 3, no. 52 (2018): 3121–28. http://dx.doi.org/10.1557/adv.2018.501.

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AbstractWide bandgap Cd1-xZnxTe (CZT) and Cd1-xMgxTe (CMT) have drawn attention as top cells in tandem devices. These materials allow tuning of the band gap over a wide range by controlling the Zn or Mg concentration with little alteration to the base CdTe properties. Historically, CdS has been used as a heterojunction partner for CZT or CMT devices. However, these devices show a significant lower open circuit voltage (VOC) than expected for wide bandgap absorbers. Recent modelling work suggests that poor band alignment between the CdS emitter and absorber results in a high concentration of holes at the interface, which increased recombination and limits the VOC. This recombination should be exacerbated for wider bandgap absorbers such as CZT and CMT. In this study, we use numerical simulations with SCAPS-1D software to investigate the band alignment in the front contacts for wider bandgap CdTe based absorbers. Results show that by replacing the CdS with a wide bandgap emitter layer, the VOC can be greatly improved, though under certain conditions, the fill factor remains sensitive to the location of the emitter conduction band. As a result, different transparent front contacts were also investigated to determine a device structure required to produce a high performance CZT or CMT top-cell for tandems devices.

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Yuan, Chao, Riley Hanus, and Samuel Graham. "A review of thermoreflectance techniques for characterizing wide bandgap semiconductors’ thermal properties and devices’ temperatures." Journal of Applied Physics 132, no. 22 (December 14, 2022): 220701. http://dx.doi.org/10.1063/5.0122200.

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Thermoreflectance-based techniques, such as pump–probe thermoreflectance (pump–probe TR) and thermoreflectance thermal imaging (TTI), have emerged as the powerful and versatile tools for the characterization of wide bandgap (WBG) and ultrawide bandgap (UWBG) semiconductor thermal transport properties and device temperatures, respectively. This Review begins with the basic principles and standard implementations of pump–probe TR and TTI techniques, illustrating that when analyzing WBG and UWBG materials or devices with pump–probe TR or TTI, a metal thin-film layer is often required. Due to the transparency of the semiconductor layers to light sources with sub-bandgap energies, these measurements directly on semiconductors with bandgaps larger than 3 eV remain challenging. This Review then summarizes the general applications of pump–probe TR and TTI techniques for characterizing WBG and UWBG materials and devices where thin metals are utilized, followed by introducing more advanced approaches to conventional pump–probe TR and TTI methods, which achieve the direct characterizations of thermal properties on GaN-based materials and the channel temperature on GaN-based devices without the use of thin-film metals. Discussions on these techniques show that they provide more accurate results and rapid feedback and would ideally be used as a monitoring tool during manufacturing. Finally, this Review concludes with a summary that discusses the current limitations and proposes some directions for future development.

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Kizilyalli, Isik C., Olga Blum Spahn, and Eric P. Carlson. "(Invited) Recent Progress in Wide-Bandgap Semiconductor Devices for a More Electric Future." ECS Transactions 109, no. 8 (September 30, 2022): 3–12. http://dx.doi.org/10.1149/10908.0003ecst.

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Wide-bandgap (WBG) semiconductors, with their excellent electrical properties, offer breakthrough performance in power electronics enabling low losses, high switching frequencies, and high temperature operation. WBG semiconductors, such as silicon carbide and gallium nitride, are likely candidates to replace silicon in the near future for high power applications as silicon is fast approaching its performance limits. Wide-bandgap power semiconductor devices enable breakthrough circuit performance and energy efficiency gains in a wide range of potential applications. The U.S. Department of Energy’s Advanced Research Project Agency - Energy (ARPA-E) has invested in WBG semiconductors over the past ten years targeting the barriers to widespread adoption of WBGs in power electronics including material and device development. Under ARPA-E projects, medium voltage (10-20kV) WBG device development has commenced to push the voltage boundaries of WBGs. This includes super-junction devices and light triggered photoconductive devices for MV applications. The WBG MV devices will enable MVDC grid distribution applicable to markets including electrified transportation, renewable interconnections, and offshore oil, gas, and wind production. Advanced WBG device ideas are additionally being explored including 3D device structures, WBG integrated circuits, and neutron detectors The progress and challenges of the WBG devices being developed under ARPA-E programs will be reviewed along with thoughts on the future trends of WBG device development.

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Rahman, Md Wahidur, Chandan Joishi, Nidhin Kurian Kalarickal, Hyunsoo Lee, and Siddharth Rajan. "High-Permittivity Dielectric for High-Performance Wide Bandgap Electronic Devices." ECS Meeting Abstracts MA2022-02, no. 32 (October 9, 2022): 1210. http://dx.doi.org/10.1149/ma2022-02321210mtgabs.

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In this presentation, we will review recent work on the integration of high permittivity dielectrics with wide and and ultra-wide bandgap semiconductor devices to obtain improved high power and high frequency applications. We will first discuss the use of such structures for vertical power devices. The high permittivity dielectrics help to reduce surface fields and therefore prevent tunnel leakage from Schottky barriers [1]. Insertion of high permittivity dielectrics can also enable better field termination in high voltage vertical devices [2]. We will discuss recent results using such high permittivity dielectrics in vertical device structures based on Gallium Oxide, leading to high vertical electric fields up to 5.7 MV/cm being sustained in the structure. We will discuss the application of these high permittivity dielectrics for three-terminal high frequency [3] and high voltage [4,5] wide bandgap transistor applications. In lateral transistors built from wide and ultra-wide bandgap semiconductors, gate breakdown and non-uniform electric fields lead to average device breakdown fields that are significantly lower than material limits. We will show how high permittivity dielectrics inserted between the gate and drain can prevent gate breakdown, and also create much more uniform electric field profiles. An analytical model to explain this will be presented and compared with 2-dimensional device simulations. Finally, we will show experimental results for lateral devices from the high Al-composition AlGaN [6], -Ga2O3[7], and AlGaN/GaN [8] material systems, where in each case, we are able to achieve state-of-art breakdown performance for devices such as lateral Schottky diodes and transistors. For example, we have achieved up to 8.3 MV/cm field in high Al-content AlGaN devices, >5.5 MV/cm in -Ga2O3-based transistors, and >3 MV/cm lateral electric field in AlGaN/GaN HEMTs. The high breakdown fields also enable us to achieve state-of-art switching figures of merit in these devices. The authors acknowledge funding from NNSA ETI Consortium, AFOSR GAME MURI Program (Program Manager Dr. Ali Sayir), AFOSR (Program Manager Dr. Kenneth Goretta) NSF ECCS- and the DARPA DREAM program (Program Manger Dr. YK Chen), managed by ONR (Program Manager Dr. Paul Maki) for support of the work. References [1] Xia, Zhanbo, et al. "Metal/BaTiO3/β-Ga2O3 dielectric heterojunction diode with 5.7 MV/cm breakdown field." Applied Physics Letters 115.25 (2019): 252104. [2] Lee, Hyun-Soo, et al. "High-permittivity dielectric edge termination for vertical high voltage devices." Journal of Computational Electronics 19.4 (2020): 1538-1545. [3] Xia, Zhanbo, et al. "Design of transistors using high-permittivity materials." IEEE Transactions on Electron Devices 66.2 (2019): 896-900. [4] Kalarickal, Nidhin Kurian, et al. "Electrostatic engineering using extreme permittivity materials for ultra-wide bandgap semiconductor transistors." IEEE Transactions on Electron Devices 68.1 (2020): 29-35. [5] Hanawa, Hideyuki, et al. "Numerical Analysis of Breakdown Voltage Enhancement in AlGaN/GaN HEMTs With a High-k Passivation Layer." IEEE Transactions on Electron Devices 61.3 (2014): 769-775. [6] Razzak, Towhidur, et al. "BaTiO3/Al0. 58Ga0. 42N lateral heterojunction diodes with breakdown field exceeding 8 MV/cm." Applied Physics Letters 116.2 (2020): 023507. [7] Kalarickal, Nidhin Kurian, et al. "β-(Al0.18Ga0.82)2O3/Ga2O3 Double Heterojunction Transistor With Average Field of 5.5 MV/cm." IEEE Electron Device Letters 42.6 (2021): 899-902. [8] Rahman, Mohammad Wahidur, et al. "Hybrid BaTiO3/SiNx/AlGaN/GaN lateral Schottky barrier diodes with low turn-on and high breakdown performance." Applied Physics Letters 119.1 (2021): 013504.

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Cheng, Zhe. "(Invited, Digital Presentation) Thermal Conductance across Heterogeneously Integrated Interfaces for Thermal Management of Wide and Ultra-Wide Bandgap Electronics." ECS Meeting Abstracts MA2022-01, no. 31 (July 7, 2022): 1318. http://dx.doi.org/10.1149/ma2022-01311318mtgabs.

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Thermal management is important for wide and ultra-wide bandgap power electronics because overheating degrades device reliability and performance. High thermal conductivity substrates such as SiC and diamond facilitate heat dissipation of these devices while the thermal boundary resistance between devices and substrates accounts for a large portion of the total thermal resistance, which prevents devices from taking the full advantage of the high thermal conductivity of the substrates. Recently, heterogeneously integrated wide and ultra-wide bandgap semiconductor interfaces are found to have low thermal boundary resistances, which provides a new degree of freedom to design and fabricate thermally conductive interfaces for thermal management of related power devices. For example, GaN can be bonded with single crystal SiC or single crystal diamond directly at room temperature. β-Ga2O3 can be bonded with SiC with or without Al2O3 interfacial layers. Compared with growth, the bonded interfaces are not limited by lattice mismatch. Moreover, the room-temperature bonding process discussed in this talk can possibly eliminate the effects of thermal stress existed in high temperature growth or bonding techniques. Recent progresses in this sub-area will be discussed in this talk, especially thermal conductance across surface-activated bonded GaN and β-Ga2O3 interfaces measured by time-domain thermoreflectance (TDTR) and the effects of thermal boundary resistance values on device temperatures. Finally, the potential challenges will also be pointed out, for instance, high-throughput thermal measurements of buried interfaces, thermal property-structure relations of interfaces bonded under different conditions, theoretical understanding of interfacial thermal transport, and device demonstrations.

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Kizilyalli, Isik C., Olga Blum Spahn, and Eric P. Carlson. "(Invited) Recent Progress in Wide-Bandgap Semiconductor Devices for a More Electric Future." ECS Meeting Abstracts MA2022-02, no. 37 (October 9, 2022): 1344. http://dx.doi.org/10.1149/ma2022-02371344mtgabs.

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Wide-bandgap (WBG) semiconductors, with their excellent electrical properties, offer breakthrough performance in power electronics enabling low losses, high switching frequencies, and high temperature operation. WBG semiconductors are likely candidates to replace silicon-based semiconductors in the near future seeing as Silicon is fast approaching its performance limits for high power requirements. Wide-bandgap power semiconductor devices offer breakthrough circuit performance enabling low losses, high switching frequencies, and high temperature operation which will allow for enormous energy efficiency gains in a wide range of potential applications. In the past ten years, the U.S. Department of Energy’s Advanced Research Project Agency - Energy (ARPA-E), which was established to fund creative, out-of-the-box, transformational energy technologies that are too early for private-sector investment, has invested in WBG semiconductors including material and device-centric programs along with application specific programs targeting the barriers to widespread adoption in power electronics. Under these ARPA-E programs, medium voltage (10-20kV) WBG device development has commenced to push the voltage boundaries of the devices including the development of WBG super-junction devices. Light triggered photoconductive WBG devices are also being investigated for MV applications. The WBG MV devices will enable MVDC grid distribution applicable to markets including electrified transportation, renewable interconnections, and offshore oil, gas, and wind production. Other WBG device ideas are also being explored under ARPA-E programs including WBG integrated circuits and neutron detectors. The progress and challenges of the WBG devices being developed under ARPA-E programs will be reviewed along with thoughts on the future trends of WBG device development.

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Sampayan, S. E., Mihail Bora, Craig Brooksby, G. J. Caporaso, Adam Conway, Steve Hawkins, Brad Hickman, et al. "High Voltage Wide Bandgap Photoconductive Switching." Materials Science Forum 821-823 (June 2015): 871–74. http://dx.doi.org/10.4028/www.scientific.net/msf.821-823.871.

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High gain photoconductive switching using Si and GaAs was studied previously for pulsed high voltage switching. A laser is used to generate charge carriers within the material to render the bulk conductive. We have begun the study of photoconductive switching using wide bandgap materials. These materials appear to operate in a non-high gain mode and the on resistance can be directly controlled with the laser intensity over many decades. It is presently believed that the conduction mechanism may be due to (a) excitation of deep states or (b) multi-photon pumping of carriers from the valance band. We present the study of the physics processes and development of a device operating at >20-kV.

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Qin, Bingchao, Dongyang Wang, Xixi Liu, Yongxin Qin, Jin-Feng Dong, Jiangfan Luo, Jing-Wei Li, et al. "Power generation and thermoelectric cooling enabled by momentum and energy multiband alignments." Science 373, no. 6554 (July 8, 2021): 556–61. http://dx.doi.org/10.1126/science.abi8668.

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Thermoelectric materials transfer heat and electrical energy, hence they are useful for power generation or cooling applications. Many of these materials have narrow bandgaps, especially for cooling applications. We developed SnSe crystals with a wide bandgap (Eg ≈ 33 kBT) with attractive thermoelectric properties through Pb alloying. The momentum and energy multiband alignments promoted by Pb alloying resulted in an ultrahigh power factor of ~75 μW cm–1 K–2 at 300 K, and an average figure of merit ZT of ~1.90. We found that a 31-pair thermoelectric device can produce a power generation efficiency of ~4.4% and a cooling ΔTmax of ~45.7 K. These results demonstrate that wide-bandgap compounds can be used for thermoelectric cooling applications.

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Saadeh, Osama, Ahmad Al-Hmoud, and Zakariya Dalala. "Characterization Circuit, Gate Driver and Fixture for Wide-Bandgap Power Semiconductor Device Testing." Electronics 9, no. 5 (April 25, 2020): 703. http://dx.doi.org/10.3390/electronics9050703.

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The world is currently experiencing major advancement in the electrification of both the industrial and commercial sectors. This is part of an effort to reduce reliance on combustible fuels, reduce emissions, integrate renewable energy systems and increase efficiency. Due to the complexity of modern circuits and systems, any circuit’s design should start with proper simulation and device selection, to reduce overall cost and time of prototyping, both of which require accurate and thorough device characterization. Wide bandgap (WBG) power semiconductor devices offer superior characteristics over conventional devices, including faster switching speeds, higher breakdown voltage, lower losses, and higher operating temperature. These properties call for special test circuits and procedures for accurate characterization. In this work, custom characterization circuits and fixtures, suitable for WBG devices are designed, tested, and described. The circuits measure several of the main characteristics of voltage controlled WBG power switches. Different technology devices were tested and characterized.

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Loong, Ling Jin, Chockalingam Aravind Vaithilingam, Gowthamraj Rajendran, and Venkatkumar Muneeswaran. "Modelling and analysis of vienna rectifier for more electric aircraft applications using wide band-gap materials." Journal of Physics: Conference Series 2120, no. 1 (December 1, 2021): 012027. http://dx.doi.org/10.1088/1742-6596/2120/1/012027.

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Abstract This paper presents a comprehensive study on the switching effects of wide bandgap devices and the importance of power electronics in an aircraft application. Silicon (Si), silicon carbide (SiC), and gallium nitride (GaN) are wide bandgap devices that act as a power electronic switch in the AC-DC converter for More Electric Aircraft (MEA) applications. Therefore, it is important to observe their converting efficiency to identify the most suitable wide bandgap device among three devices for AC-DC converters in aircraft applications to provide high efficiency and high-power density. In this study, the characteristics of Si, SIC, and GaN devices are simulated using PSIM software. Also, this paper presents the performance of the Vienna rectifier for aircraft application. The Vienna rectifier using Si, SiC, and GaN devices are simulated using PSIM software for aircraft application. GaN with Vienna rectifier provides better performance than Si and SiC devices for aircraft applications among the three devices. It gives high efficiency, high power density, low input current THD to meet IEEE-519 standard, and high-power factor at mains.

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Ahn, Byung Tae, Liudmila Larina, Ki Hwan Kim, and Soong Ji Ahn. "Development of new buffer layers for Cu(In,Ga)Se2 solar cells." Pure and Applied Chemistry 80, no. 10 (January 1, 2008): 2091–102. http://dx.doi.org/10.1351/pac200880102091.

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Recent progress in the field of Cu(In,Ga)Se2 (CIGS) thin film solar cell technology is briefly reviewed. New wide-bandgap Inx(OOH,S)y and ZnSx(OH)yOz buffers for CIGS solar cells have been developed. Advances have been made in the film deposition by the growth process optimization that allows the control of film properties at the micro- and nanolevels. To improve the CIGS cell junction characteristics, we have provided the integration of the developed Cd-free films with a very thin CdS film. Transmittances of the developed buffers were greatly increased compared to the standard CdS. Inx(OOH,S)y buffer has been applied to low-bandgap CIGS devices which have shown poor photovoltaic properties. The experimental results obtained suggest that low efficiency can be explained by unfavorable conduction band alignment at the Inx(OOH,S)y/CIGS heterojunction. The application of a wide-gap Cu(In,Ga)(Se,S)2 absorber for device fabrication yields the conversion efficiency of 12.55 %. As a result, the Inx(OOH,S)y buffer is promising for wide-bandgap Cu(In,Ga)(Se,S)2 solar cells, however, its exploration for low-bandgap CIGS devices will not allow a high conversion efficiency. The role played by interdiffusion at the double-buffer/CIGS heterojunction and its impact on the electronic structure and device performance has also been discussed.

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Bindra, Ashok. "Joint Electronic Device Engineering Council JC-70 for Wide-Bandgap Devices [Society News]." IEEE Power Electronics Magazine 4, no. 4 (December 2017): 77. http://dx.doi.org/10.1109/mpel.2017.2762429.

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Agarwal, Anant, Woong Je Sung, Laura Marlino, Pawel Gradzki, John Muth, Robert Ivester, and Nick Justice. "Wide Band Gap Semiconductor Technology for Energy Efficiency." Materials Science Forum 858 (May 2016): 797–802. http://dx.doi.org/10.4028/www.scientific.net/msf.858.797.

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The attributes and benefits of wide-bandgap (WBG) semiconductors are rapidly becoming known, as their use in power electronics applications continues to gain industry acceptance. However, hurdles still exist in achieving widespread market acceptance, on a par with traditional silicon power devices. Primary challenges include reducing device costs and the expansion of a workforce trained in their use. The Department of Energy (DOE) is actively fostering development activities to expand application spaces, achieve acceptable cost reduction targets and grow the acceptance of WBG devices to realize DOEs core missions of more efficient energy generation, greenhouse gas reduction and energy security within the U.S. This paper discusses currently funded activities and application areas that are suitable for WBG introduction. A detailed cost roadmap for SiC device introduction is also presented.

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Kumar, Ashok, Mustaque A. Khan, and Mahesh Kumar. "Recent advances in UV photodetectors based on 2D materials: a review." Journal of Physics D: Applied Physics 55, no. 13 (November 19, 2021): 133002. http://dx.doi.org/10.1088/1361-6463/ac33d7.

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Abstract Since the discovery of graphene there has been a strong interest in two-dimensional (2D) materials among the scientific community due to their extraordinary properties. Although ultraviolet (UV) photodetectors based on bulk wide bandgap semiconductors exhibit a good response, their photodetection performance significantly diminishes as their thickness is reduced to atomic scale, due to poor absorption and surface dangling bonds. 2D layered materials are free of dangling bonds and have a layer-dependent tunable bandgap and optoelectronic properties. Even an atomically thin layer of a 2D material shows high absorption due to strong light–matter interaction. 2D materials are attracting a lot of attention due to their compatibility with flexible, wearable devices and the ease of making van der Waals heterostructures. Although graphene and transition metal dichalcogenides have shorter band gaps, these materials can be easily integrated with other wide bandgap materials for UV detection, and such integration has often produced extraordinary device performance. Also, low bandgap, strong UV-absorbing 2D materials can be utilised for UV detection by using an optical bandpass filter. Recently, wide-bandgap 2D materials such as gallium sulphide (GaS), hexagonal boron nitride (hBN), and bismuth oxychlorides (BiOCls) have been explored for application in UV photodetection. Many of these wide bandgap materials show extraordinary UV photodetection performance.

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Shenai, K. "A Critique of Wide Bandgap (WBG) Power Semiconductor Device Datasheets." ECS Transactions 64, no. 7 (August 8, 2014): 13–17. http://dx.doi.org/10.1149/06407.0013ecst.

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Wang, Xiang Guo, and Masayuki Yamamoto. "A Study on Fastening the Switching Speed for Wide Bandgap Semiconductor Based Super Cascode." Materials Science Forum 963 (July 2019): 823–26. http://dx.doi.org/10.4028/www.scientific.net/msf.963.823.

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The Super Cascode is a series connected structure with a normally-off low voltage Si-MOSFET and multiple normally-on wide bandgap semiconductors. It has low switching losses compared with silicon based bipolar devices, and low on-resistance and low cost compared with other single high voltage normally-off wide bandgap semiconductor devices. In practice, however, there are inevitable parasitic inductances, which result in the increase of switching losses. The method is proposed to eliminate the common-source inductances (CSIs), such as using stack-die configuration with each device and adding an additional inductance in the gate loop of Si-MOSFET. It is numerically shown that the rise and fall times of the proposed method were 33.5% and 7.2% faster than the conventional one, respectively.

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Ma, Yunlong, Zhenjing Kang, and Qingdong Zheng. "Recent advances in wide bandgap semiconducting polymers for polymer solar cells." Journal of Materials Chemistry A 5, no. 5 (2017): 1860–72. http://dx.doi.org/10.1039/c6ta09325f.

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Carlson, Eric P., Daniel W. Cunningham, Yan Zhi Xu, and Isik C. Kizilyalli. "Power Electronic Devices and Systems Based on Bulk GaN Substrates." Materials Science Forum 924 (June 2018): 799–804. http://dx.doi.org/10.4028/www.scientific.net/msf.924.799.

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Wide-bandgap power semiconductor devices offer enormous energy efficiency gains in a wide range of potential applications. As silicon-based semiconductors are fast approaching their performance limits for high power requirements, wide-bandgap semiconductors such as gallium nitride (GaN) and silicon carbide (SiC) with their superior electrical properties are likely candidates to replace silicon in the near future. Along with higher blocking voltages wide-bandgap semiconductors offer breakthrough relative circuit performance enabling low losses, high switching frequencies, and high temperature operation. ARPA-E’s SWITCHES program, started in 2014, set out to catalyze the development of vertical GaN devices using innovations in materials and device architectures to achieve three key aggressive targets: 1200V breakdown voltage (BV), 100A single-die diode and transistor current, and a packaged device cost of no more than ȼ10/A. The program is drawing to a close by the end of 2017 and while no individual project has yet to achieve all the targets of the program, they have made tremendous advances and technical breakthroughs in vertical device architecture and materials development. GaN crystals have been grown by the ammonothermal technique and 2-inch GaN wafers have been fabricated from them. Near theoretical, high-voltage (1700-4000V) and high current (up to 400A pulsed) vertical GaN diodes have been demonstrated along with innovative vertical GaN transistor structures capable of high voltage (800-1500V) and low RON (0.36-2.6 mΩ-cm2). The challenge of selective area doping, needed in order to move to higher voltage transistor devices has been identified. Furthermore, a roadmap has been developed that will allow high voltage/current vertical GaN devices to reach ȼ5/A to ȼ7/A, realizing functional cost parity with high voltage silicon power transistors.

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Ji, Dong, and Srabanti Chowdhury. "On the Progress Made in GaN Vertical Device Technology." International Journal of High Speed Electronics and Systems 28, no. 01n02 (March 2019): 1940010. http://dx.doi.org/10.1142/s012915641940010x.

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Silicon technology enabled most of the electronics we witness today, including power electronics. However, wide bandgap semiconductors are capable of addressing high-power electronics more efficiently compared to Silicon, where higher power density is a key driver. Among the wide bandgap semiconductors, silicon carbide (SiC) and gallium nitride (GaN) are in the forefront in power electronics. GaN is promising in its vertical device topology. From CAVETs to MOSFETs, GaN has addressed voltage requirements over a wide range. Our current research in GaN offers a promising view of GaN that forms the theme of this article. CAVETs and OGFETs (a type of MOSFET) in GaN are picked to sketch the key achievements made in GaN vertical device over the last decade.

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Alamoudi, Hadeel, Bin Xin, Somak Mitra, Mohamed N. Hedhili, Singaravelu Venkatesh, Dhaifallah Almalawi, Norah Alwadai, Zohoor Alharbi, Ahmad Subahi, and Iman S. Roqan. "Enhanced solar-blind deep UV photodetectors based on solution-processed p-MnO quantum dots and n-GaN p–n junction-structure." Applied Physics Letters 120, no. 12 (March 21, 2022): 122102. http://dx.doi.org/10.1063/5.0083259.

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Obtaining p-type wide-bandgap semiconductors with a bandgap >3.5 eV is still challenging. Here, p–n junction devices based on wide-bandgap (≥4 eV) p-type MnO quantum dots (QDs) and n-type Si-doped GaN are fabricated. The p-MnO QDs are synthesized by cost-effective femtosecond laser ablation in liquid. A simple spray-coating method is used for fabricating the p-MnO/n-GaN-based solar-blind deep UV (DUV) photodetector. X-ray diffraction, transmission electron microscopy, and Raman spectroscopy reveal the MnO QD crystal structure. X-ray photoelectron microscopy analysis reveals good band alignment between p-MnO QDs and n-GaN, demonstrating the (type-II) staggered band alignment p–n heterojunction-based device. Electrical and photocurrent measurements show a high photocurrent response with a low dark current, while superior photo-responsivity (∼2530 mA/W) is achieved, along with self-powered and visible-blind characteristics (265 nm cutoff), demonstrating a high-performance DUV device with high detection limit for low light level applications. This study provides insights into the potential of p-type MnO QDs for III-nitride p–n junction DUV devices.

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Li, Jiahao, Yanda Ji, Rui Pan, Run Zhao, Ye Yuan, Weiwei Li, and Hao Yang. "Fowler-Nordheim tunneling in β-Ga₂O₃/SrRuO₃ Schottky interfaces." Journal of Physics D: Applied Physics 55, no. 21 (February 25, 2022): 210003. http://dx.doi.org/10.1088/1361-6463/ac5356.

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Abstract Interfaces in heterostructures always emerge as prototype electronic devices with tunable functionality. The fundamental properties of these interfaces can be finely manipulated by epitaxy engineering. Recently, heterostructures based on Ga2O3, an ultra-wide bandgap semiconductor, have been reported for use in high powered device applications. Herein, we will demonstrate a heterostructure of β-Ga2O3/SrRuO3 integrated on c-plane sapphire, where the high density of edge dislocations are evidenced in the heterostructure interfaces. Apart from the dominant Schottky emission mechanism, Fowler-Nordheim tunneling is also revealed by leakage current analysis, which may be ascribed to the edge dislocations at the interfaces. These results boost the basic understanding of ultra-wide bandgap materials and devices.

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Biswas, Abhijit, Mingfei Xu, Kai Fu, Jingan Zhou, Rui Xu, Anand B. Puthirath, Jordan A. Hachtel, et al. "Properties and device performance of BN thin films grown on GaN by pulsed laser deposition." Applied Physics Letters 121, no. 9 (August 29, 2022): 092105. http://dx.doi.org/10.1063/5.0092356.

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Wide and ultrawide-bandgap semiconductors lie at the heart of next-generation high-power, high-frequency electronics. Here, we report the growth of ultrawide-bandgap boron nitride (BN) thin films on wide-bandgap gallium nitride (GaN) by pulsed laser deposition. Comprehensive spectroscopic (core level and valence band x-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman) and microscopic (atomic force microscopy and scanning transmission electron microscopy) characterizations confirm the growth of BN thin films on GaN. Optically, we observed that the BN/GaN heterostructure is second-harmonic generation active. Moreover, we fabricated the BN/GaN heterostructure-based Schottky diode that demonstrates rectifying characteristics, lower turn-on voltage, and an improved breakdown capability (∼234 V) as compared to GaN (∼168 V), owing to the higher breakdown electrical field of BN. Our approach is an early step toward bridging the gap between wide and ultrawide-bandgap materials for potential optoelectronics as well as next-generation high-power electronics.

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Wang, Xin, Zongtao Wang, Mingwei Li, Lijun Tu, Ke Wang, Dengping Xiao, Qiang Guo, et al. "A New Dibenzoquinoxalineimide-Based Wide-Bandgap Polymer Donor for Polymer Solar Cells." Polymers 14, no. 17 (August 30, 2022): 3590. http://dx.doi.org/10.3390/polym14173590.

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The molecular design of a wide-bandgap polymer donor is critical to achieve high-performance organic photovoltaic devices. Herein, a new dibenzo-fused quinoxalineimide (BPQI) is successfully synthesized as an electron-deficient building block to construct donor–acceptor (D–A)-type polymers, namely P(BPQI-BDT) and P(BPQI-BDTT), using benzodithiophene and its derivative, which bears different side chains, as the copolymerization units. These two polymers are used as a donor, and the narrow bandgap (2,20-((2Z,20Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo [3,4-e]thieno[2,″30′:4′,50]thieno[20,30:4,5]pyrrolo[3,2g]thieno[20,30:4,5]thieno[3,2-b]indole-2,10 diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) Y6 is used as an acceptor to fabricate bulk heterojunction polymer solar cell devices. Y6, as a non-fullerene receptor (NFA), has excellent electrochemical and optical properties, as well as a high efficiency of over 18%. The device, based on P(BPQI-BDTT):Y6, showed power conversion efficiencies (PCEs) of 6.31% with a JSC of 17.09 mA cm−2, an open-circuit voltage (VOC) of 0.82 V, and an FF of 44.78%. This study demonstrates that dibenzo-fused quinoxalineimide is a promising building block for developing wide-bandgap polymer donors.

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Bandyopadhyay, Avra S., Gustavo A. Saenz, and Anupama Kaul. "Characterization of Few layer Tungsten diselenide based FET under Thermal Excitation." MRS Advances 2, no. 60 (2017): 3721–26. http://dx.doi.org/10.1557/adv.2017.490.

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Abstract:Two-dimensional (2D) materials are very promising with respect to their integration into optoelectronic devices. Monolayer tungsten diselenide (WSe2) is a direct-gap semiconductor with a bandgap of ∼1.6eV, and is therefore a complement to other two-dimensional materials such as graphene, a gapless semimetal, and boron nitride, an insulator. The direct bandgap distinguishes monolayer WSe2 from its bulk and bilayer counterparts, which are both indirect gap materials with smaller bandgaps. This sizable direct bandgap in a two-dimensional layered material enables a host of new optical and electronic devices. In this work, a comprehensive analysis of the effect of optical excitation on the transport properties in few-layer WSe2 is studied. Monolayer WSe2 flakes from natural WSe2 crystals were transferred onto Si/SiO2 (270nm) substrates by mechanical exfoliation. The flakes were observed under an optical microscope. A FET based on mechanically exfoliated WSe2 was fabricated using photolithography with Molybdenum as metal contact and Silicon as back gate and the electronic properties were measured in a wide range of temperatures. The mobility of our device was found to be 0.2 cm /V-S at room temperature. The schottky barrier height was found to decrease from 80 meV to 25 meV as the gate voltage increases.

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Jamal-Eddine, Zane, Yuewei Zhang, and Siddharth Rajan. "Recent Progress in III-Nitride Tunnel Junction-Based Optoelectronics." International Journal of High Speed Electronics and Systems 28, no. 01n02 (March 2019): 1940012. http://dx.doi.org/10.1142/s0129156419400123.

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Tunnel junctions have garnered much interest from the III-Nitride optoelectronic research community within recent years. Tunnel junctions have seen applications in several material systems with relatively narrow bandgaps as compared to the III-Nitrides. Although they were initially dismissed as ineffective for commercial device applications due to high voltage penalty and on resistance owed to the wide bandgap nature of the III-Nitride material systems, recent development in the field has warranted further study of such tunnel junction enabled devices. They are of particular interest for applications in III-Nitride optoelectronic devices in which they can be used to enable novel device designs which could potentially address some of the most challenging physical obstacles presented with this unique material system. In this work we review the recent progress made on the study of III-Nitride tunnel junction-based optoelectronic devices and the challenges which are still faced in the field of study today.

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Morvan, Erwan, Alexandre Kerlain, Christian Dua, and Christian Brylinski. "Influence of Material Properties on Wide-Bandgap Microwave Power Device Characteristics." Materials Science Forum 433-436 (September 2003): 731–36. http://dx.doi.org/10.4028/www.scientific.net/msf.433-436.731.

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32

Oshima, Yuichi, and Elaheh Ahmadi. "Progress and challenges in the development of ultra-wide bandgap semiconductor α-Ga₂O₃ toward realizing power device applications." Applied Physics Letters 121, no. 26 (December 26, 2022): 260501. http://dx.doi.org/10.1063/5.0126698.

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Ultra-wide-bandgap (UWBG) semiconductors, such as Ga2O3 and diamond, have been attracting increasing attention owing to their potential to realize high-performance power devices with high breakdown voltage and low on-resistance beyond those of SiC and GaN. Among numerous UWBG semiconductors, this work focuses on the corundum-structured α-Ga2O3, which is a metastable polymorph of Ga2O3. The large bandgap energy of 5.3 eV, a large degree of freedom in band engineering, and availability of isomorphic p-type oxides to form a hetero p–n junction make α-Ga2O3 an attractive candidate for power device applications. Promising preliminary prototype device structures have been demonstrated without advanced edge termination despite the high dislocation density in the epilayers owing to the absence of native substrates and lattice-matched foreign substrates. In this Perspective, we present an overview of the research and development of α-Ga2O3 for power device applications and discuss future research directions.

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33

Gunshor, Robert L., and Arto V. Nurmikko. "II-VI Blue-Green Laser Diodes: A Frontier of Materials Research." MRS Bulletin 20, no. 7 (July 1995): 15–19. http://dx.doi.org/10.1557/s088376940003712x.

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The current interest in the wide bandgap II-VI semiconductor compounds can be traced back to the initial developments in semiconductor optoelectronic device physics that occurred in the early 1960s. The II-VI semiconductors were the object of intense research in both industrial and university laboratories for many years. The motivation for their exploration was the expectation that, possessing direct bandgaps from infrared to ultraviolet, the wide bandgap II-VI compound semiconductors could be the basis for a variety of efficient light-emitting devices spanning the entire range of the visible spectrum.During the past thirty years or so, development of the narrower gap III-V compound semiconductors, such as gallium arsenide and related III-V alloys, has progressed quite rapidly. A striking example of the current maturity reached by the III-V semiconductor materials is the infrared semiconductor laser that provides the optical source for fiber communication links and compact-disk players. Despite the fact that the direct bandgap II-VI semiconductors offered the most promise for realizing diode lasers and efficient light-emitting-diode (LED) displays over the green and blue portions of the visible spectrum, major obstacles soon emerged with these materials, broadly defined in terms of the structural and electronic quality of the material. As a result of these persistent problems, by the late 1970s the II-VI semiconductors were largely relegated to academic research among a small community of workers, primarily in university research laboratories.

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34

Bercu, Nicolas, Mihai Lazar, Olivier Simonetti, Pierre Michel Adam, Mélanie Brouillard, and Louis Giraudet. "KPFM - Raman Spectroscopy Coupled Technique for the Characterization of Wide Bandgap Semiconductor Devices." Materials Science Forum 1062 (May 31, 2022): 330–34. http://dx.doi.org/10.4028/p-c35702.

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A non-destructive technique for the characterization of the doped regions inside wide bandgap (WBG) semiconductor structures of power devices is presented. It consists in local measurements of the surface potential by Kelvin Probe Force Microscopy (KPFM) coupled to micro-Raman spectroscopy. The combined experiments allow to visualize the space charge extent of the doped region using the near-field mapping and to estimate its dopant concentration using the Raman spectroscopy. The technique has been successfully applied for the characterization of a WBG SiC (silicon carbide) device.

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35

Goorsky, Mark S., Michael Evan Liao, Kenny Huynh, Yekan Wang, Brandon Carson, Lezli Matto, and Aviram Bhalla-Levine. "(Invited) Heterogeneous Materials Integration for Wide Bandgap Semiconductors." ECS Meeting Abstracts MA2022-02, no. 37 (October 9, 2022): 1347. http://dx.doi.org/10.1149/ma2022-02371347mtgabs.

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The study of interfaces for both epitaxial and wafer-bonded systems draws from materials science, electrical engineering, and mechanical engineering and involves advanced materials characterization techniques. Low temperature wafer bonding has been leveraged to produce a wide array of materials combinations, most notably silicon-on-insulator structures. However, bonded interfaces can impact the electrical or thermal transport across such interfaces. In this presentation, we provide a few examples in semiconductor-based systems to address the ability to study and modify different, technologically important, interface combinations as a function of processing, such as annealing. The materials combinations primarily involve wide bandgap materials combinations including GaN|Si to b-Ga2O3 | SiC as well as bonding to single crystal diamond. In addition, we describe the role of the relative lattice orientation across semiconductor-semiconductor interfaces on transport properties and polarization engineering to producing high performance heterointerfaces. Our main goal is to be able to study and engineer the interfaces to optimize properties and ultimately, device performance.

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Shur, Michael S., and M. Asif Khan. "GaN/AIGaN Heterostructure Devices: Photodetectors and Field-Effect Transistors." MRS Bulletin 22, no. 2 (February 1997): 44–50. http://dx.doi.org/10.1557/s0883769400032565.

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In this article, we review recent progress in GaN-based photodetectors and field-effect transistors (FETs), including optoelectronic FETs, and discuss materials parameters and fabrication technologies that determine the device characteristics of these two device families. Many types of visible-blind photodetectors and nearly all types of FETs have been demonstrated in GaN-based materials systems. However many challenges remain, both in improving the existing devices—the performance of which is still quite far from reaching its full potential—and in developing entirely new devices, which use unique properties of this wide-bandgap materials system.

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37

Chen, Bingbing, Pengyang Wang, Ningyu Ren, Renjie Li, Ying Zhao, and Xiaodan Zhang. "Tin dioxide buffer layer-assisted efficiency and stability of wide-bandgap inverted perovskite solar cells." Journal of Semiconductors 43, no. 5 (May 1, 2022): 052201. http://dx.doi.org/10.1088/1674-4926/43/5/052201.

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Abstract Inverted perovskite solar cells (IPSCs) have attracted tremendous research interest in recent years due to their applications in perovskite/silicon tandem solar cells. However, further performance improvements and long-term stability issues are the main obstacles that deeply hinder the development of devices. Herein, we demonstrate a facile atomic layer deposition (ALD) processed tin dioxide (SnO2) as an additional buffer layer for efficient and stable wide-bandgap IPSCs. The additional buffer layer increases the shunt resistance and reduces the reverse current saturation density, resulting in the enhancement of efficiency from 19.23% to 21.13%. The target device with a bandgap of 1.63 eV obtains open-circuit voltage of 1.19 V, short circuit current density of 21.86 mA/cm2, and fill factor of 81.07%. More importantly, the compact and stable SnO2 film invests the IPSCs with superhydrophobicity, thus significantly enhancing the moisture resistance. Eventually, the target device can maintain 90% of its initial efficiency after 600 h storage in ambient conditions with relative humidity of 20%–40% without encapsulation. The ALD-processed SnO2 provides a promising way to boost the efficiency and stability of IPSCs, and a great potential for perovskite-based tandem solar cells in the near future.

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38

Stabach, Jennifer, Zach Cole, Chad B. O'Neal, Brice McPherson, Robert Shaw, and Brandon Passmore. "A High Performance Power Package for Wide Bandgap Semiconductors Using Novel Wire Bondless Power Interconnections." International Symposium on Microelectronics 2015, no. 1 (October 1, 2015): 000353–58. http://dx.doi.org/10.4071/isom-2015-wp16.

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Silicon carbide (SiC) wide bandgap semiconductor power device technologies offer improved electrical and thermal performance over silicon in high performance power electronic applications, such as hybrid or fully electric vehicles, aerospace, solar inverters, and advanced military systems. However, current packaging limitations make it difficult to operate these devices to their full potential. One such limitation includes die interconnections, which are traditionally made using large diameter aluminum wire bonds. This discussion introduces an innovative wire bondless interconnect technique for power packaging called PowerStep. This approach includes a precision etched metal tab with raised regions matching the size and location of device terminals and trenches to accommodate critical features on devices such as passivated surfaces. The tab offers a low profile, low inductance, low resistance, high electrical and thermal conductivity, and mechanically rugged interconnection solution. PowerStep has been implemented to facilitate a single-step interconnection method for a 600 to 1700 V SiC electronics package, replacing wire bonds which are connected one at a time. In addition, a key element of this package is the absence of a baseplate, resulting in lower weight, volume, and cost, as well as reduced manufacturing complexity. The electrical, thermal, and mechanical characteristics of PowerStep interconnections are analyzed and compared to conventional aluminum wire bonds to demonstrate the advantages of wire bondless interconnections coupled with wide bandgap devices. The low parasitics and junction-to-case thermal resistance of the package combined with PowerStep interconnects capture the high performance of SiC for power applications.

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Cui, Hao, Zizheng Qin, Haohang Sun, Zhanguo Chen, and Weiping Qin. "Near-infrared light excitation of h-BN ultra-wide bandgap semiconductor." Applied Physics Letters 121, no. 24 (December 12, 2022): 241101. http://dx.doi.org/10.1063/5.0131613.

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We demonstrate a method to faithfully excite an ultra-wide bandgap semiconductor hexagonal boron nitride (h-BN) by using optical frequency upconversion technology. By means of Yb3+ and Tm3+ as dual bridging sensitizers, NaYF4:Yb3+, Tm3+, and Gd3+ microcrystals were excited by near-infrared light and generated high-energy (>6 eV) excited states. We fabricated a photoelectric conversion device by attaching the microcrystals to the surfaces of the h-BN thin film. When the device was irradiated with 980-nm near-infrared light, the Gd3+ ions in the microcrystals were populated to the high-energy excited states 5GJ through an internal 7-photon process, emitting 205 nm deep ultraviolet fluorescence and 195.3 nm vacuum ultraviolet fluorescence, which provided enough energy for h-BN photoexcitation. Dynamic analysis showed that Förster resonance energy transfer played a very important role in the optical excitation, and populating Gd3+ ions to high-energy excited states was the technical key.

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40

Zhao, Qiang, Michael Lukitsch, Jie Xu, Gregory Auner, Ratna Niak, and Pao-Kuang Kuo. "Development of Wide Bandgap Semiconductor Photonic Device Structures by Excimer Laser Micromachining." MRS Internet Journal of Nitride Semiconductor Research 5, S1 (2000): 852–58. http://dx.doi.org/10.1557/s1092578300005172.

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Excimer laser ablation rates of Si (111) and AlN films grown on Si (111) and r-plane sapphire substrates were determined. Linear dependence of ablation rate of Si (111) substrate, sapphire and AlN thin films were observed. Excimer laser micromachining of the AlN thin films on silicon (111) and SiC substrates were micromachined to fabricate a waveguide structure and a pixilated structure. This technique resulted in clean precise machining of AlN with high aspect ratios and straight walls.

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41

Zhang, Xuan, Chengcheng Yao, Cong Li, Lixing Fu, Feng Guo, and Jin Wang. "A Wide Bandgap Device-Based Isolated Quasi-Switched-Capacitor DC/DC Converter." IEEE Transactions on Power Electronics 29, no. 5 (May 2014): 2500–2510. http://dx.doi.org/10.1109/tpel.2013.2287501.

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Shikata, Shinichi. "Potential and Challenges of Diamond Wafer Toward Power Electronics." International Journal of Automation Technology 12, no. 2 (March 1, 2018): 175–78. http://dx.doi.org/10.20965/ijat.2018.p0175.

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To achieve a 50% worldwide reduction of CO2by the middle of this century, development of energy saving power device technology using wide bandgap materials is urgently needed. Diamond is receiving increasing attention as a next generation material for wide bandgap semiconductors owing to its extreme characteristics. Research studies investigating large wafers, low resistivity, and low dislocation have accelerated. This study targets the use of wafers for power electronics applications, and the required machining technologies for diamond, including wafer shaping, slicing, and surface finishing, are introduced.

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Ikenoue, Takumi, Satoshi Yoneya, Masao Miyake, and Tetsuji Hirato. "Epitaxial Growth and Bandgap Control of Ni1-xMgxO Thin Film Grown by Mist Chemical Vapor Deposition Method." MRS Advances 5, no. 31-32 (2020): 1705–12. http://dx.doi.org/10.1557/adv.2020.219.

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ABSTRACTWide-bandgap oxide semiconductors have received significant attention as they can produce devices with high output and breakdown voltage. p-Type conductivity control is essential to realize bipolar devices. Therefore, as a rare wide-bandgap p-type oxide semiconductor, NiO (3.7 eV) has garnered considerable attention. In view of the heterojunction device with Ga2O3 (4.5–5.0 eV), a p-type material with a large bandgap is desired. Herein, we report the growth of a Ni1-xMgxO thin film, which has a larger bandgap than NiO, on α-Al2O3 (0001) substrates that was developed using the mist chemical vapor deposition method. The Ni1-xMgxO thin films epitaxially grown on α-Al2O3 substrates showed crystallographic orientation relationships identical to those of NiO thin films. The Mg composition of Ni1-xMgxO was easily controlled by the Mg concentration of the precursor solution. The Ni1-xMgxO thin film with a higher Mg composition had a larger bandgap, and the bandgap reached 3.9 eV with a Ni1-xMgxO thin film with x = 0.28. In contrast to an undoped Ni1-xMgxO thin film showing insulating properties, the Li-doped Ni1-xMgxO thin film had resistivities of 101–105 Ω∙cm depending on the Li precursor concentration, suggesting that Li effectively acts as an acceptor.

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44

Pan, James, Shamima Afroz, Scott Suko, James D. Oliver, and Thomas Knight. "High Workfunction, Compound Gate Metal Engineering for Low DIBL, High Gain, High Density Advanced RF Power Static Induction Transistor (SIT) and HV Schottky Diode in 4H Silicon Carbide." Materials Science Forum 924 (June 2018): 641–44. http://dx.doi.org/10.4028/www.scientific.net/msf.924.641.

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Wide bandgap semiconductors, such as 4H SiC, are suitable for power regulating devices, due to compatibility with conventional process integration, high breakdown voltage and thermal conductivity [1]. For RF applications, in order to achieve better switching speed, high cut off frequency, and low series resistance (Rdson), it is essential to choose the right gate metals [2]. Engineering of the gate metals not only improves the critical device parameters by adjustment of the metal workfunction, but also affects how the high aspect ratio trenches are filled for a next generation SIT device configuration [3] - [5].

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45

Reese, Samantha, Kelsey Horowitz, Timothy Remo, and Margaret Mann. "Regional Manufacturing Cost Structures and Supply Chain Considerations for SiC Power Electronics in Medium Voltage Motor Drives." Materials Science Forum 924 (June 2018): 518–22. http://dx.doi.org/10.4028/www.scientific.net/msf.924.518.

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With the growth in wide bandgap (WBG) semiconductors, specifically Silicon Carbide (SiC), the technology has matured enough to highlight a need to understand the drivers of manufacturing cost, regional manufacturing costs, and plant location decisions. Further, ongoing research and investment, necessitates analytical analysis to help inform development of wide bandgap technologies. The paper explores the anticipated device, module, and motor drive cost at volume manufacturing. It additional outlines the current regional contributors to the supply chain and proposes how the base models can be used to evaluate the cost reduction potential of proposed research advances.

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Jiang, Qi, Jinhui Tong, Rebecca A. Scheidt, Xiaoming Wang, Amy E. Louks, Yeming Xian, Robert Tirawat, et al. "Compositional texture engineering for highly stable wide-bandgap perovskite solar cells." Science 378, no. 6626 (December 23, 2022): 1295–300. http://dx.doi.org/10.1126/science.adf0194.

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The development of highly stable and efficient wide-bandgap (WBG) perovskite solar cells (PSCs) based on bromine-iodine (Br–I) mixed-halide perovskite (with Br greater than 20%) is critical to create tandem solar cells. However, issues with Br–I phase segregation under solar cell operational conditions (such as light and heat) limit the device voltage and operational stability. This challenge is often exacerbated by the ready defect formation associated with the rapid crystallization of Br-rich perovskite chemistry with antisolvent processes. We combined the rapid Br crystallization with a gentle gas-quench method to prepare highly textured columnar 1.75–electron volt Br–I mixed WBG perovskite films with reduced defect density. With this approach, we obtained 1.75–electron volt WBG PSCs with greater than 20% power conversion efficiency, approximately 1.33-volt open-circuit voltage ( V oc ), and excellent operational stability (less than 5% degradation over 1100 hours of operation under 1.2 sun at 65°C). When further integrated with 1.25–electron volt narrow-bandgap PSC, we obtained a 27.1% efficient, all-perovskite, two-terminal tandem device with a high V oc of 2.2 volts.

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Wang, Yen Po, Hsin Chieh Li, Yan Chi Huang, and Chih Shan Tan. "Synthesis and Applications of Halide Perovskite Nanocrystals in Optoelectronics." Inorganics 11, no. 1 (January 11, 2023): 39. http://dx.doi.org/10.3390/inorganics11010039.

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The perovskites used for optoelectronic devices have been more attractive during recent years due to their wide variety of advantages, such as their low cost, high photoluminescence quantum yield (PLQY), high carrier mobility, flexible bandgap tunability, and high light absorption ability. However, optoelectronic applications for traditional inorganic and organic materials present dilemmas due to their hardly tunable bandgap and instability. On the other hand, there are some more important benefits for perovskite nanocrystals, such as a size-dependent bandgap and the availability of anion exchange at room temperature. Therefore, perovskite NC-based applications are currently favored, offering a research direction beyond perovskite, and much research has focused on the stability issue and device performance. Thus, the synthesis and applications of perovskite NCs need to be thoroughly discussed for the future development of solar cells, light-emitting diodes, photodetectors, and laser research.

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Mi, Zetian, Ping Wang, David Laleyan, and Yuanpeng Wu. "(Invited) Monolayer h-BN: Epitaxy, Properties, and Emerging Device Applications." ECS Meeting Abstracts MA2022-01, no. 20 (July 7, 2022): 1107. http://dx.doi.org/10.1149/ma2022-01201107mtgabs.

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Hexagonal boron nitride (h-BN) has shown tremendous promise when used alongside other two-dimensional (2D) materials such as graphene, and as a wide-bandgap semiconductor for deep-ultraviolet optoelectronics and quantum photonics. Owing to its large bandgap energy comparable or higher than Al(Ga)N, h-BN can be used to form heterostructures to address some of the critical challenges of Al(Ga)N-based systems. To date, however, many fundamental material properties of h-BN remain unknown. For example, its bandgap energy remains under debate, with reports spanning from 5.9 to 6.5 eV. There is also strong controversy as to whether h-BN has a direct or indirect bandgap. In this context, We have studied the epitaxy of h-BN by using ultrahigh temperature (up to 1850 °C) plasma-assisted molecular beam epitaxy (MBE) on sapphire, Ni and HOPG substrates. We show that, when grown at sufficiently high temperature, h-BN can exhibit predominantly excitonic emission at ~220 nm. The measured luminescence intensity is orders of magnitude higher than AlN under identical conditions. By forming a p-i-n structure using this high-quality h-BN as the active region, the current-voltage (I-V) and electroluminescence characteristics of a first demonstration of a h-BN deep UV LED will be reported.

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Onyeaju, M. C., A. N. Ikot, C. A. Onate, E. Aghemenloh, and H. Hassanabadi. "Electronic states in core/shell GaN/YxGa1−xN quantum well (QW) with the modified Pöschl–Teller plus Woods–Saxon potential in the presence of electric field." International Journal of Modern Physics B 31, no. 15 (March 7, 2017): 1750119. http://dx.doi.org/10.1142/s0217979217501193.

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The electronic states of a core/shell quantum well (QW) system confined in a modified Pöschl–Teller (PT) plus Woods–Saxon (WS) potential in the presence of electric field are studied with the III-Nitride group owing to their wide bandgap for device applications. The bandgap energy in this regard is obtained by solving analytically the Schrödinger wave equation with the Pekeris-type approximation to the centrifugal term.

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Seo, Jung-Hun. "Editorial for the Special Issue on Wide Bandgap Semiconductor Based Micro/Nano Devices." Micromachines 10, no. 3 (March 26, 2019): 213. http://dx.doi.org/10.3390/mi10030213.

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Journal articles on the topic 'Wide bandgap device'

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