Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"Ga)Se2"”.
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Reversible Relaxationsphänomene imelektrischen Transport von Cu(In,Ga)Se2
Untersucht werden reversible Relaxationsphänomene Mit großen Relaxationszeiten (einige Stunden bei 300K) im elektrischen Transport von p-leitenden CIGS- Schichten und ZnO/CdS/CIGS-Solarzellen. ein wichtiger Effekt ist die Voc-Relaxation der Zellen d.h. langsame Anstieg Leerlaufspannung (Voc) unter …
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Photoluminescence study of Cu(In,Ga)Se2 and Cu2ZnSnSe4 used for thin film solar cells
… the question why the best laboratory size CuIn1-xGaxSe2-based (CIGSe) solar cells have been achieved at about 30% Ga, whereas the optimal band gap requires much higher Ga content (around 50%). Also for the first time ever we examined the effects of 4 keV Ar+ irradiation on optical properties of …
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Effect of Alkali on the Efficiency and Reliability of Cu(In,Ga)Se2 Solar Cells
… bid to realize greater than 20% efficient Cu(In,Ga)Se<sub>2</sub>(CIGS) solar cells. Achieving high efficiency is one key parameter for the success of a photovoltaic technology but so is its long-term stability. In this thesis, the relationship between the performance of alkali treated …
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Beleuchtungsabhängiger Ladungstransport durch tiefe kompensierende Störstellen in CdTe- und Cu(In,Ga)Se 2 -Solarzellen
… durch Beleuchtung der CdTe- bzw. Cu(In,Ga)Se2-Solarzelle Modelle vorgestellt. Diese Modelle basieren auf der Kompensation der Dotierung des CdS bzw. CdTe durch tiefe Störzellen. Die Modelle wurden simuliert und mit gemessenen Daten verglichen.
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Defektspektroskopie an Solarzellen und Schottky-Kontakten auf Basis des Halbleiters Cu(In,Ga)Se 2
Solarzellen auf Basis des Halbleiters Cu(In,Ga)Se2 (CIGS) sind dabei, die Grenze zur Kommerzialisierung zu überschreiten. Ein Spitzenwirkungsgrad von bisher knapp 19% verspricht ein großes Potential. Leider hinkt das physikalische Verständnis den technologischen Erfolgen hinterher. In der …
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{112} Polar Surfaces of Copper(indium,gallium)selenide: Properties and Effects on Crystal Growth
Cu(In,Ga)Se2 (GIGS) are promising materials for thin film photovoltaic applications. This work studies the epitaxial growth of CIGS single crystal films on GaAs substrates of various orientations and characterizes the properties of the thin films. A surprising finding is the strong tendency of film …
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Cu2ZnSn(S,Se)4 photovoltaic absorber fabrication by hydride chalcogenization of electrodeposited precursors
… related to the commercially available Cu(In,Ga)Se2 (CIGS) absorber material, CZTSSe consists of more readily-available materials, and may therefore offer cost reduction and highly scalable production potential if its PV properties can be controlled and improved. This work presents a two-step …
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Physical and optoelectronic properties of copper silver indium diselenide thin films
… the compounds it is possible to change the bandgap of the material in order to collect sunlight more efficiently. A promising alloy for tunable bandgap solar cells is the (Cu,Ag)(In,Ga)Se2 system. The focus of my dissertation is to perform a comprehensive characterization of the structural and …
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Imaging as characterization techniques for thin-film cadmium telluride photovoltaics
… defects that limit performance. This study began with developing EL, PL, and dark lock-in thermography (DLIT) for CdTe. Once imaging data were acquired, luminescence and thermography signatures of non-uniformities that disrupt the generation and collection of carriers were identified and …
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Optical characterization of copper indium gallium diselenide thin films
Cu(In,Ga)Se2 (CIGS) and its alloys are the leading choice for thin film photovoltaic absorber layers due to their high performance in devices, low degradation, high optical absorption coefficient and high tolerance to off-stoichiometry and intrinsic defects. Film conductivity and recombination …
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Growth and characterization of epitaxial silver indium diselenide
… solar cell absorber material to date is Cu(In,Ga)Se2 (CIGS). While current efficiency records are over 21% for single-junction cells, there is still room for improvement. Replacing some of the Cu with Ag has been shown to be beneficial in CIGS devices. However, the Ag- containing chalcopyrites …
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Characterization Of Microstructural And Chemical Features In Cu-in-ga-se-s-based Thin-film Solar Cells
… characterized for changes in the CIGS (Cu(In,Ga)Se2) microstructure due to sodium incorporation from soda-lime glass or from a post-deposition treatment with NaF as a function of CIGS deposition temperature. The CIGS-CdS interface becomes smoother and the small columnar CIGS grains close to …
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How visual representations affect undergraduate students’ use and understanding of engineering concepts during problem solving
In this two-part thesis, I address gaps in the surface science of semiconductor materials for photovoltaics and discipline-based education research literature. Surface Science of Semiconductor Materials for Photovoltaics With the rise of global energy consumption, it is important to find low-cost, …
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Elektronische und chemische Eigenschaften von Grenzflächen und Oberflächen in optimierten Cu(In,Ga)(S,Se)2 Dünnschichtsolarzellen
… Dünnschichtsolarzellen auf der Basis von Cu(In,Ga)(S,Se)2, der heute vielversprechendsten Dünnschichttechnologie, durchgeführt. Für eine weitere Optimierung der Zellen ist ein detailliertes Verständnis ihrer chemischen, elektronischen und strukturellen Eigenschaften notwendig. Insbesondere die …
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Studies on monolithic tandem structure for low cost and high efficiency dye-sensitized solar cells
… By comparison the thin lm technology, Cu(In,Ga)Se2 or CIGS, is currently being manufactured for use commercially at a competitive price and performance to the current market leader, silicon. A tandem solar cell comprised of the DSC and CIGS absorbers has shown promise of an efficiency …
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Optical Modeling of Solar Cells
… layers and tandem cells. Experimentally investigating these combinations to optimize cell performance is expensive and time consuming. Computer simulations of the optical and electrical functions allow for eliminating large class of ineffective combinations and containing the parameter space …