Tesis sobre el tema "Molecular Thin film"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Molecular Thin film".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Okazaki, Nobuharu. "Molecular rectification with identical metal electrodes at low temperatures". Thesis, University of Exeter, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251190.
Texto completoHeutz, Sandrine Elizabeth Monique. "Structural, spectroscopic and morphological properties of molecular thin film heterostructures". Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252184.
Texto completoGilchrist, James. "Nanoscale analysis of molecular photovoltaic thin film structures and interfaces". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/25023.
Texto completoHu, Yanhong. "Molecular dynamics studies of thin film nucleation and substrate modification". [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000955.
Texto completoSingh, Rajeev. "Experimental characterization of thin film thermoelectric materials and film deposition via molecular beam epitaxy /". Diss., Digital Dissertations Database. Restricted to UC campuses, 2008. http://uclibs.org/PID/11984.
Texto completoSchünemann, Christoph. "Organic Small Molecules: Correlation between Molecular Structure, Thin Film Growth, and Solar Cell Performance". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-105169.
Texto completoThe aim of this thesis is to demonstrate correlations between the molecular structure of small organic molecules, their arrangement in thin films, and the solar cell performance. For structure analysis of the organic thin films, the combination of variable angle spectroscopic ellipsometry (VASE) and grazing incidence X-ray diffraction (GIXRD) as complementary methods turned out to be a powerful combination. Using both methods, it is possible to obtain information about the crystallinity, crystallite size, intermolecular arrangement, mean molecular orientation, optical constants n and k, and phase separation within thin films. In addition, the topography of thin films is analyzed by atomic force microscopy. First, the thin film morphology of pristine zinc-phthalocyanine (ZnPc) films deposited at different substrate temperatures (Tsub=30°C, 60°C, 90°C) and for varying film thicknesses (5, 10, 25, 50 nm) is investigated. The ZnPc films grow highly crystalline with an upright standing molecular orientation with respect to the substrate surface for all investigated Tsub and all film thicknesses. In effcient organic solar cells, donor and acceptor molecules are commonly co-deposited to form a blend absorber film. This is usually accompanied by a certain phase separation between donor and acceptor molecules leads to a formation of percolation paths necessary to extract electrons and holes towards the electrodes. For ZnPc:C60 blends the origin of this phase separation process is analyzed by investigating different degrees of phase separation induced by film deposition at different Tsub (30°C, 100°C, 140°C) and for different blend ratios (6:1, ... , 1:6 (vol%)). GIXRD measurements indicate that the preferred crystallization of C60 is the driving force for good phase separation. Solar cells with improved phase separation of ZnPc:C60 blends (Tsub=140°C, 1:1) reveal a better charge carrier extraction and thus enhanced effciencies of 3.0% in comparison to 2.5% for the reference device (Tsub=30°C, 1:1). In the second part, the impact of molecular orientation within the absorber thin films on light harvesting is examined for pristine ZnPc and diindenoperylene (DIP) films. For film deposition on weakly interacting substrates like glass, SiO2, amorphous organic transport films, or C60, the orientation of DIP and ZnPc molecules is found to be upright standing. In contrast, GIXRD and VASE measurements show that films deposited onto strongly interacting substrates like Au and Ag, as well as on thin PTCDA templating layers lead to nearly flat-lying ZnPc and DIP molecules. Since the molecular transition dipole moment is oriented in the plane of the DIP and ZnPc molecules, the light absorption in films with flat-lying molecules is strongly improved. Unfortunately, an implementation of Au or Ag sublayers in organic solar cells does not result in reliable dependencies since the enhanced absorption by an improved molecular orientation is superimposed by different effects like microcavity and plasmonic effects. The implementation of PTCDA interlayers leads to transport barriers making the solar cell data interpretation difficult. In the last part, the influence of molecular structure on thin film growth is studied for DIP and its derivatives Ph4-DIP and P4-Ph4-DIP, isoviolanthrone, and Bis-nFl-NTCDI derivatives. GIXRD measurements reveal that steric hindrance is induced by the addition of side chains (for Bis-nFl-NTCDI) and phenyl rings (for Ph4-DIP and P4-Ph4-DIP) (N,N-Bis(fluorene-2-yl)-naphthalenetetra-carboxylic diimide) leading to an amorphous thin film growth. In contrast, DIP films and Bis-HFl-NTCDI films are found to be crystalline. The mean molecular orientation and hence the absorption is strongly affected by the different growth modes of DIP and its derivatives. In OSC, the presence of the phenyl rings prevents an effcient phase separation for (P4-)Ph4-DIP:C60 blends which causes diminished charge extraction in comparison to the crystalline DIP:C60 blends. For the Bis-nFl-NTCDI series, the transport properties are significantly worse in the amorphous films composed of Bis-nFl-NTCDI derivatives with alkyl chains in comparison to the nanocrystalline films made of the bare Bis-HFl-NTCDI
Yu, Shun. "Molecular Interaction of Thin Film Photosensitive Organic Dyes on TiO2 Surfaces". Doctoral thesis, KTH, Materialfysik, MF, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-47354.
Texto completoQC 20111114
Kim, Younggu. "Novel organic polymeric and molecular thin-film devices for photonic applications". College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/4164.
Texto completoThesis research directed by: Department of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Wu, Yu. "Control of pentacene thin film growth by supersonic molecular beam deposition". [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2008. http://irs.ub.rug.nl/ppn/.
Texto completoNakamura, Tomoya. "Molecular Orientation Control of Organic Semiconducting Materials for Thin Film Electronics". Kyoto University, 2019. http://hdl.handle.net/2433/242523.
Texto completoZugic, Richard. "Modelling the tribology of thin film interfaces". Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365788.
Texto completoSingh, Lovejeet. "The influence of film thickness and molecular weight on the thermal properties of ultrathin polymer films". Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/11043.
Texto completoKadhim, N. J. "Morphological imperfections associated with molecular beam epitaxial growth of GaAs layers". Thesis, University of Hertfordshire, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377702.
Texto completoLloyd, Adam L. "Modelling silver thin film growth on zinc oxide". Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/24860.
Texto completoEffertz, Christian [Verfasser]. "Organic molecular crystals: from thin-films to devices : investigation of thin-film formation and electronic transport properties of polycrystalline perylene films / Christian Effertz". Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2011. http://d-nb.info/1018191550/34.
Texto completoShioya, Nobutaka. "Development of Analytical Technique of Molecular Orientation in a Thin Film and Its Application to Low-Crystallinity Organic Thin Films Having a Surface Roughness". Kyoto University, 2018. http://hdl.handle.net/2433/232268.
Texto completoSavoy, Steven Michael. "Molecular thin film/high temperature superconductor heterostructures : deposition, characterization and energy transfer /". Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Texto completoMuirhead, Ian T. "An evolution in molecular beam epitaxy (MBE) techniques for optical thin film coatings". Thesis, Heriot-Watt University, 1991. http://hdl.handle.net/10399/849.
Texto completoHsu, Chih-Hao. "Hierarchical Supramolecular Structures based on Molecular Nanoparticles from Bulk to Thin Film State". University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1406630381.
Texto completoAbdullah, Isam. "Nanoscale properties of molecular and oxide based thin film devices measured by SPM". Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/94080/.
Texto completoBorovikov, Valery V. "Multi-scale Simulations of Thin-Film Metal Epitaxial Growth". University of Toledo / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1216928358.
Texto completoOguz, Cihan. "Control-oriented modeling of discrete configuration molecular scale processes applications in polymer synthesis and thin film growth /". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19867.
Texto completoCommittee Chair: Gallivan, Martha A.; Committee Member: Hess, Dennis; Committee Member: Lee, Jay H.; Committee Member: Li, Mo; Committee Member: Ludovice, Pete.
Alleman, Coleman. "Molecular Dynamics Investigations of Polystyrene-Based Binary Thin Film Systems: Interfacial Properties and Mechanical Behavior". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306909005.
Texto completoGoktepe, Canan. "Water Soluble Monomer Grafting On Thin Films Of Ultra High Molecular Weight Polyethylene". Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1081546/index.pdf.
Texto completo#947
-ray in air. Also characterizations of pure, irradiated and grafted films were made by applying gravimetric, spectroscopic, thermal and mechanic tests. The thin films of UHMWPE were prepared by using compression molding. AA and MAA grafting on thin UHMWPE films were carried out by surface grafting and xylene-swollen grafting methods. During grafting processes, homopolymerization of monomers was avoided by using Fe2+ and Cu2+ ions. Grafting degree of AA and MAA were calculated for the samples irradiated at different doses. To verify grafting of AA and MAA on UHMWPE films, FTIR spectra of grafted films were used. Metal-uptake capacity is important property of grafted polyethylene for environmental applications. Thus, we examined metal-uptake capacities of AA and MAA grafted films for Fe(III) and Ni (II) and it was found that AA and MAA grafted UHMWPE films showed good affinity towards Fe(III) and Ni(II) metals. Thermal behavior of films were examined by DSC analysis. First run and second run DSC thermograms showed the thermal stability of films under heat. Mechanical properties of UHMWPE decrease with irradiation and grafting. However stress at break values of xylene-swollen grafted samples tend to increase with irradiation dose. In conclusion, water soluble monomers were successfully grafted on UHMWPE and these AA and MAA grafted UHMWPE films can be used in biomedical, environmental applications and other related areas.
Mandru, Andrada Oana. "Ferromagnetic Thin and Ultra-Thin Film Alloys of Manganese and Iron with Gallium and Their Structural, Electronic, and Magnetic Properties". Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1458572741.
Texto completoBradley, Christopher Simon. "The synthesis and characterisation of Langmuir-Blodgett film forming TCNQ adducts". Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/19388/.
Texto completoWu, Zhenghao. "Investigating the Effects of Grafting and Chain Stiffness on Nanoconfined Polymers from Molecular Dynamics Simulation". University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1525861929889197.
Texto completoYu, Samuel Shing Chi. "Covalent Attachment of Nanoscale Organic Films to Carbon Surfaces". Thesis, University of Canterbury. Chemistry, 2008. http://hdl.handle.net/10092/4083.
Texto completoHeidarian, Alireza. "Study of the Static and Dynamic Magnetization across the First Order Phase Transition in FeRh Thin Films". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-198693.
Texto completoDoherty, Walter John. "POLYMER-MEDIATED ELECTROCHEMISTRY IN SOL-GEL THIN FILMS AND SPECTROELECTROCHEMICAL CHARACTERIZATION OF MOLECULAR ADLAYERS ON INDIUM-TIN OXIDE ELECTRODE SURFACES". Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1233%5F1%5Fm.pdf&type=application/pdf.
Texto completoMares, Jeremy. "EPITAXIAL GROWTH, CHARACTERIZATION AND APPLICATION OF NOVEL WIDE BANDGAP OXIDE SEMICONDUCTORS". Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3002.
Texto completoPh.D.
Optics and Photonics
Optics and Photonics
Optics PhD
Lawrence, A. J. "Modeling the Optical Response to a Near-Field Probe Tip from a Generalized Multilayer Thin Film". PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2328.
Texto completoMerchan, Alvarez Lina Paola. "Alkane fluids confined and compressed by two smooth gold crystalline surfaces: pure liquids and mixtures". Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47551.
Texto completoBelova, Valentina Verfasser] y Frank [Akademischer Betreuer] [Schreiber. "Correlation between Structural Properties and Intermolecular Coupling in Molecular Donor/Acceptor Thin Film Heterostructures / Valentina Belova ; Betreuer: Frank Schreiber". Tübingen : Universitätsbibliothek Tübingen, 2018. http://d-nb.info/117067237X/34.
Texto completoBelova, Valentina [Verfasser] y Frank [Akademischer Betreuer] Schreiber. "Correlation between Structural Properties and Intermolecular Coupling in Molecular Donor/Acceptor Thin Film Heterostructures / Valentina Belova ; Betreuer: Frank Schreiber". Tübingen : Universitätsbibliothek Tübingen, 2018. http://d-nb.info/117067237X/34.
Texto completoZykov, Anton. "On the understanding of organic thin film growth and the changes in structure formation induced by molecular chemical tuning". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17710.
Texto completoFunctional organic molecules are promising for the application in future relevant technologies such as organic light emitting diodes (OLEDs), solar cells, transistors and bio-sensors. One of the processing methods to fabricate organic devices is organic molecular beam deposition. In this process, the complexly interacting molecules grow via self-assembly as thin films on a substrate. Due to the close structure-property relationship, the growth process constitutes a highly interesting and important scientific challenge for both application oriented as well as fundamental research and is the topic of the present thesis. The experimental results and conceptual methods presented in this thesis contribute new stimuli to the understanding of the molecular self-assembly. The demonstrated influence of chemical tuning on various facets of structure formation, such as film roughness, crystal phase purity and molecular diffusivities, uncovers the strong potential of this approach for steering organic growth. Therefore, the present work has implications for future research and application of functional organic thin films.
Schünemann, Christoph Verfasser], Karl [Akademischer Betreuer] [Leo y Manfred [Akademischer Betreuer] Stamm. "Organic Small Molecules: Correlation between Molecular Structure, Thin Film Growth, and Solar Cell Performance / Christoph Schünemann. Gutachter: Karl Leo ; Manfred Stamm. Betreuer: Karl Leo". Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://d-nb.info/1068443944/34.
Texto completoSchünemann, Christoph [Verfasser], Karl [Akademischer Betreuer] Leo y Manfred [Akademischer Betreuer] Stamm. "Organic Small Molecules: Correlation between Molecular Structure, Thin Film Growth, and Solar Cell Performance / Christoph Schünemann. Gutachter: Karl Leo ; Manfred Stamm. Betreuer: Karl Leo". Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-105169.
Texto completoAdamovic, Dragan. "Molecular Dynamics Studies of Low-Energy Atom Impact Phenomena on Metal Surfaces during Crystal Growth". Doctoral thesis, Linköpings universitet, Teoretisk Fysik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-7165.
Texto completoOn the day of the defence date the status of article II was Accepted.
Isaacs, Steven Ray. "Molecular Assembly of Monolayer-Protected Gold Nanoparticles and their Chemical, Thermal, and Ultrasonic Stabilities". TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3048.
Texto completoPippenger, Phillip McKinney. "Photoluminescence of crystalline thin film buckminsterfullerene". Thesis, 1995. http://hdl.handle.net/1911/13983.
Texto completoSu, Che-Wei y 蘇哲暐. "Molecular Dynamics Simulation of thin film growth". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/51951036289647608448.
Texto completo國立中央大學
光電科學研究所
91
Optical coating is a process in which a theoretical design is put into practice. The key to a successful production of high-quality thin film faithful to its original design is the choice and precise control of environment parameters during the deposition process. However, the relation between those parameters and the characteristics of thin film is not completely understood yet. Moreover, experiments have not been able to provide enough information with regard to the dynamic behavior and mechanism of thin film in the formation process and its microstructure and characteristics. Therefore this study takes a different approach and makes use of molecular dynamics simulation to construct a two-dimensional simulation system. Substrate temperature, incident kinetic energy, deposition rate, and incident angle are variables. The simulation results are then discussed to investigate the effects of the various environment parameters on thin film.
Wu, Jin-Yin y 鄔經英. "Study of Self-Assembled Multilayer Molecular Thin Film". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/93996314903398104084.
Texto completo國立中正大學
化學研究所
85
Self-organized molecular thin films with well-defined structure and orienation are gaining wide attention for their potential application such as opto-electronic device and biomembranes. The purpose of this research is prepare multilayer film with C60 molecule as the bridge between layers. Based on the fact that C60 forms charge-transfer complex with amine moiety at low temperature, a facile process is designed to achieve the multilayer. Quartz, silicon wafer were used as the substrate for film build-up. The film structure was characterized by reflection-absorption IR, ellipsometry, contact angle measurement and UV spectroscopy.
Lee, Tsung-Han y 李宗翰. "Molecular Dynamics Simulation for Au-Pt Thin Film Deposition". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31810642453366729178.
Texto completo"Elastic Properties of Molecular Glass Thin Films". Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.9351.
Texto completoDissertation/Thesis
Ph.D. Chemical Engineering 2011
Hung, Jun-Xian y 黃俊憲. "Study on the Molecular Beam Deposition of CuInSe2 Thin Film". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/07051813663172868817.
Texto completo國立中山大學
電機工程學系研究所
91
The objective of this proposed study is to develop the new material CuInSe2 for large area, low cost and high efficiency commercial CuInSe2 based solar cell for the solar resource in Taiwan. The compositions of CuInSe2 films are modulated precisely to obtain an ideal electrical and optical characteristics resulting in high conversion efficiency for commercial solar cell applications. Numerous experimental investigations have shown the electrical properties of undoped CuInSe2 are dominated by various types of electrically active intrinsic defects caused by the deviations from the ideal stoichiometry. Without any intentional doping CuInSe2 can be made n-type and p-type conducting with carrier concentrations varying over many orders of magnitude either by slightly changing the composition of the material during growth or by appropriate post-growth annealing procedures. Several attempts have been made successfully by the crucial construction and application of intrinsic defect chemistry model to investigate the trend in the conductivity of CuInSe2, however, there investigation still remain no clear evidence to directly correlate composition and electrical properties reported by several authors, and the results of experimental data shows in contradiction to the intrinsic defect model. According to the point defect model, that samples with DX<0 and larger values of |DY| are always n-type conducting, and sample with DX>0 and DY>0 are always p-type conducting. In addition, as DX<0 and DY<0, the dominant defect pair calculated from the point defect model is VCu and InCu, their concentrations varies as a function of DY. Once DY is relatively more negative, [VCu] increase and that forms [VCu]>[InCu]. Therefore, the electrical conductivity of CuInSe2 changed from n-type to p-type. The Growth model of MBE is considered to investigate the reactive mechanism of epitaxial growth. At 500℃, the BEP of In and Cu molecular beam fluxes supplied were 5×10-8~5×10-7 torr for the MBE growth of CuInSe2 films. The change of Se molecular beam flux not only affect the composition of CuInSe2 films, but also the deviation from molecularity DX and the deviation from valence stoichiometry. As Se molecular beam flux increase to 10-6 torr, the concentrations of dominant defects show to decrease about three orders. Thus, the increase of Se BEP results in increasing the mobility as well as the conductivity. On the whole, this study is based on the simulation to investigate the mechanism of MBE. It could be used to control precisely the composition of CuInSe2 films leading to obtain the electrical characteristics for solar cell design.
Folinsky, Anna Barr. "Investigating Molecular Size Variations in Thin Film Chemical Vapor Sensors". Thesis, 2010. https://thesis.library.caltech.edu/5834/3/ABF-Ch1.pdf.
Texto completoVapor sensing arrays composed of broadly responsive, chemically sensitive detectors have been explored for many years. They have been used in fields ranging from good quality control, to environmental monitoring and explosives detection, to disease diagnostics. All of these tasks require high sensitivity and fine discrimination ability. As new challenges arise, the ability to understand the performance and improve the availability of array components becomes paramount.
This work details progress in gaining greater understanding of certain chemical substrates used in sensor arrays. Specifically, arrays using insulator/carbon black composite sensors have been prepared using either polymer or non-volatile small organic molecules as the insulating, chemically sensitive component. The crystallinity of the small molecules as compared to the polymers was determined to cause the differing formulation requirements between the polymers and the small molecules.
Additionally, arrays of sensors composed of varying molecular weights of a given polymer were examined. Very low molecular weights of polystyrene, a high glass transition temperature polymer, exhibited improved behavior and response times compared to higher molecular weights. Finally, arrays composed of varied length carboxylic and dicarboxylic acids were studied. Of these two homologous series, the arrays composed of carboxylic acids provided better discrimination than did those composed of dicarboxylic acids, suggesting the utility of sensor materials containing multiple accessible functional groups.
These studies, taken together, suggest several new ways to increase the number of compounds and chemical functionalities available to use in chemical vapor sensors. Increased sensor choice allows construction of more broadly responsive and finely discriminating sensor arrays, thereby increasing the general utility of composite vapor sensor arrays.
Schünemann, Christoph. "Organic Small Molecules: Correlation between Molecular Structure, Thin Film Growth, and Solar Cell Performance". Doctoral thesis, 2012. https://tud.qucosa.de/id/qucosa%3A26570.
Texto completoThe aim of this thesis is to demonstrate correlations between the molecular structure of small organic molecules, their arrangement in thin films, and the solar cell performance. For structure analysis of the organic thin films, the combination of variable angle spectroscopic ellipsometry (VASE) and grazing incidence X-ray diffraction (GIXRD) as complementary methods turned out to be a powerful combination. Using both methods, it is possible to obtain information about the crystallinity, crystallite size, intermolecular arrangement, mean molecular orientation, optical constants n and k, and phase separation within thin films. In addition, the topography of thin films is analyzed by atomic force microscopy. First, the thin film morphology of pristine zinc-phthalocyanine (ZnPc) films deposited at different substrate temperatures (Tsub=30°C, 60°C, 90°C) and for varying film thicknesses (5, 10, 25, 50 nm) is investigated. The ZnPc films grow highly crystalline with an upright standing molecular orientation with respect to the substrate surface for all investigated Tsub and all film thicknesses. In effcient organic solar cells, donor and acceptor molecules are commonly co-deposited to form a blend absorber film. This is usually accompanied by a certain phase separation between donor and acceptor molecules leads to a formation of percolation paths necessary to extract electrons and holes towards the electrodes. For ZnPc:C60 blends the origin of this phase separation process is analyzed by investigating different degrees of phase separation induced by film deposition at different Tsub (30°C, 100°C, 140°C) and for different blend ratios (6:1, ... , 1:6 (vol%)). GIXRD measurements indicate that the preferred crystallization of C60 is the driving force for good phase separation. Solar cells with improved phase separation of ZnPc:C60 blends (Tsub=140°C, 1:1) reveal a better charge carrier extraction and thus enhanced effciencies of 3.0% in comparison to 2.5% for the reference device (Tsub=30°C, 1:1). In the second part, the impact of molecular orientation within the absorber thin films on light harvesting is examined for pristine ZnPc and diindenoperylene (DIP) films. For film deposition on weakly interacting substrates like glass, SiO2, amorphous organic transport films, or C60, the orientation of DIP and ZnPc molecules is found to be upright standing. In contrast, GIXRD and VASE measurements show that films deposited onto strongly interacting substrates like Au and Ag, as well as on thin PTCDA templating layers lead to nearly flat-lying ZnPc and DIP molecules. Since the molecular transition dipole moment is oriented in the plane of the DIP and ZnPc molecules, the light absorption in films with flat-lying molecules is strongly improved. Unfortunately, an implementation of Au or Ag sublayers in organic solar cells does not result in reliable dependencies since the enhanced absorption by an improved molecular orientation is superimposed by different effects like microcavity and plasmonic effects. The implementation of PTCDA interlayers leads to transport barriers making the solar cell data interpretation difficult. In the last part, the influence of molecular structure on thin film growth is studied for DIP and its derivatives Ph4-DIP and P4-Ph4-DIP, isoviolanthrone, and Bis-nFl-NTCDI derivatives. GIXRD measurements reveal that steric hindrance is induced by the addition of side chains (for Bis-nFl-NTCDI) and phenyl rings (for Ph4-DIP and P4-Ph4-DIP) (N,N-Bis(fluorene-2-yl)-naphthalenetetra-carboxylic diimide) leading to an amorphous thin film growth. In contrast, DIP films and Bis-HFl-NTCDI films are found to be crystalline. The mean molecular orientation and hence the absorption is strongly affected by the different growth modes of DIP and its derivatives. In OSC, the presence of the phenyl rings prevents an effcient phase separation for (P4-)Ph4-DIP:C60 blends which causes diminished charge extraction in comparison to the crystalline DIP:C60 blends. For the Bis-nFl-NTCDI series, the transport properties are significantly worse in the amorphous films composed of Bis-nFl-NTCDI derivatives with alkyl chains in comparison to the nanocrystalline films made of the bare Bis-HFl-NTCDI.
Chia-Lin, Chang y 張家林. "Molecular dynamics simulation of thin film growth on GMR corrugated structure". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/86066480526561484853.
Texto completo國立成功大學
機械工程學系
89
This paper presents the use of molecular dynamics in simulating thin film growth on GMR corrugated structures. The simulation model mainly concerns the deposition of Co atoms on a V-shape Cu substrate. The many-body, tight-binding potential model is utilized in the MD simulation to represent the inter-atomic force which exists between the atoms. The interface width is used to quantify the variation of surface roughness at the transient and steady states. The paper investigates the influence of incident energy on the deposited film surface property and on the growing mechanism, for both vertical and oblique deposition. The results demonstrate how the growing characteristics are influenced by different incident energies and by different deposition directions. It is found that at relatively low incident energies the film growth tends to be in a 3-D cluster mode and that a void track is formed, whose growing direction is almost equal to the surface normal to the two inclined surfaces. The uneven thickness found along the base of the V-shape is mainly due to the deposited atoms which accumulate at the bottom of the V-groove when the incident energy is at a relatively high level. It is found that there exists an optimal incident energy which produces the best film surface property. The film surface property can be improved by changing the incident direction relative to two inclined directions of . Smaller deviation angles yield better film surface properties for low incident energy. Conversely, higher levels of incident energy result in worse film surface properties.
Chen, Wei-Ru y 陳瑋如. "A Micro Fabricated Vapor Preconcentrator Employing Carbon Molecular Sieve Thin Film". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/72824459597299263307.
Texto completo國立臺灣師範大學
化學系
100
In this study, the adsorption of volatile organic compounds (VOCs) by the synthesized porous carbon based film was investigated. For developing a VOC micro preconcentrator chips, we directly synthesized carbon based adsorbent film inside a pre-sealed and anodic bonded micro device. The precursor material was mixed with a solvent and injected into the chip channel to form a thin layer then pyrolyzed at high temperature and under the oxygen free atmosphere to form a microporous film. The physical properties including surface morphology, microstructure image, and BET surface area were inspected by FE-SEM and specific surface area & pore size distribution analyzer. When using cellulose as the starting material, it was slowly heated at a rate of 10 ℃/min from room temperature to 600 ℃ and maintained for two hours under high purity nitrogen atmosphere. While for saran, it was heated to a higher temperature 700 ℃ and maintained for only one hour. The BET surface area obtained was 308 m2/g and 899 m2/g, respectively, which was sufficiently comparable to many commercial adsorbents. The adsorption /desorption experiment was performed using toluene as the target VOC. It revealed that the carbon film obtained possesses very good performance where the preconcentration factor can achieve 103 to 104. Finally, we applied Wheeler model to assess the thermodynamic capacity of our synthesized adsorbent film. The carbon films in this study show good durability, reproducibility that can be applied in various designs of VOC micro preconcentrator chips.