Download or read book Preferred Orientation in Polycrystalline Cu In Ga Se2 and Its Effect on Absorber Thin films and Devices written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this work is to investigate physical properties of Cu(In, Ga)Se2 polycrystalline thin-films exhibiting a high degree of preferred orientation. Specifically, by using Na-free Cu(In, Ga)Se2 thin-films, it is intended to experimentally determine differences (if any) between films with a (110/102)-preferred orientation and films with a (112)-preferred orientation. The approach to the problem is a systematic comparative analysis of film and device properties in which the most significant variable is the preferred orientation of the Cu(In, Ga)Se2 polycrystalline absorbers. To complement the results of Na-free absorbers and devices, a microstructural analysis is presented on (110)-oriented high efficiency Cu(In, Ga)Se2 absorbers that are grown on standard Mo-coated soda-lime glass substrates.
Download or read book Cu In1 xGax Se2 Based Thin Film Solar Cells written by Subba Ramaiah Kodigala and published by Academic Press. This book was released on 2011-01-03 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cu(In1-xGax)Se2 Based Thin Film Solar Cells provides valuable contents about the fabrication and characterization of chalcopyrite Cu(In1-xGax)Se2 based thin film solar cells and modules. The growth of chalcopyrite Cu(In1-xGax)(S1-ySey)2 absorbers, buffers, window layers, antireflection coatings, and finally metallic grids, which are the sole components of solar cells, is clearly illustrated. The absorber, which contains multiple elements, segregates secondary phases if the growth conditions are not well optimized i.e., the main drawback in the fabrication of solar cells. More importantly the solutions for the growth of thin films are given in detail. The properties of all the individual layers and single crystals including solar cells analyzed by different characterization techniques such as SEM, AFM, XPS, AES, TEM, XRD, optical, photoluminescence, and Raman spectroscopy are explicitly demonstrated. The electrical analyses such as conductivities, Hall mobilities, deep level transient spectroscopy measurements etc., provide a broad picture to understand thin films or single crystals and their solar cells. The book clearly explains the working principle of energy conversion from solar to electrical with basic sciences for the chalcopyrite based thin film solar cells. Also, it demonstrates important criteria on how to enhance efficiency of the solar cells and modules. The effect of environmental factors such as temperature, humidity, aging etc., on the devices is mentioned by citing several examples. - Illustrates a number of growth techniques to prepare thin film layers for solar cells - Discusses characterization techniques such as XRD, TEM, XPS, AFM, SEM, PL, CL, Optical measurements, and Electrical measurements - Includes I-V, C-V measurements illustrations - Provides analysis of solar cell efficiency - Presents current trends in thin film solar cells research and marketing
Download or read book Japanese Journal of Applied Physics written by and published by . This book was released on 2002 with total page 1274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Role of Na and Modifications to Cu In Ga Se2 Absorber Materials Using Thin MF M written by Miguel A. Contreras and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Research written by and published by Allied Publishers. This book was released on 2003 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contributed articles with reference to India.
Download or read book Thin Films for Photovoltaic and Related Device Applications Volume 426 written by David Ginley and published by . This book was released on 1996-11-18 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been considerable progress in the development of thin-film photovoltaic devices with new efficiency records and enhanced durability. These achievements are the result of significant advances in the fundamental understanding of the materials, interfaces and devices. With 18 countries represented, this truly international volume brings together engineers and researchers from academic, industrial and national laboratories worldwide to review different materials systems and address common issues and problems. A wide variety of topics related to the development of thin-film photovoltaic and related devices, including thick-film transistors and materials for flat-panel displays, are addressed. Areas of emphasis include materials synthesis, device fabrication and characterization, and modelling. Topics include: thin-film amorphous silicon devices; thin-film silicon devices; thin-film devices based on copper-indium diselenide; cadmium-telluride devices; transparent conductive oxides and related materials for thin-film devices; and novel concepts for thin-film photovoltaics.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cu In Ga Se2 Thin Film Evolution During Growth A Photoluminescence Study Preprint written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This conference paper describes the in-depth understanding of the defect formation and resulting changes in material quality occurring during the Cu(In,Ga)Se2 growth process is vital to the successful and widespread use of this photovoltaic material. In an attempt to develop such an understanding, we investigated the growth of Cu(In,Ga)Se2 thin-films from (In,Ga)2Se3 precursors. This was achievedby using energy- and time-resolved photoluminescence spectroscopies to characterize a series of thin-films, each removed at a different point along the reaction pathway of the 'three-stage' growth process. The resulting thin-films are representative of the absorber layer as it proceeds from a Cu-rich to In(Ga)-rich state. The experimental results support a growth model incorporating defectchanges in the dominant defect states and improvement in the recombination lifetime during this final stage of the growth process as the material transitions to a Cu-poor phase.
Download or read book Wide Gap Chalcopyrites written by Susanne Siebentritt and published by Springer Science & Business Media. This book was released on 2006-02-25 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.
Download or read book Polycrystalline Semiconductors VII written by Takashi Fuyuki and published by . This book was released on 2003 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises the over 100 contributions that were presented at the International Conference on Polycrystalline Semiconductors which took place from September 10 to 13, 2002, in Nara, Japan.
Download or read book Determination and Influence of Na Supply and Se Flux During Growth of Cu In Ga Se 1tn2 Thin Films written by George Hanna and published by . This book was released on 2004 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pulsed Electrochemical Deposition of CuInSe2 and Cu In Ga Se2 Semiconductor Thin Films written by Sreekanth Mandati and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: CuInSe2 (CIS) and Cu(In,Ga)Se2 (CIGS) semiconductors are the most studied absorber materials for thin films solar cells due to their direct bandgap and large absorption coefficient. The highly efficient CIGS devices are often fabricated using expensive vacuum based technologies; however, recently electrodeposition has been demonstrated to produce CIGS devices with high efficiencies and it is easily amenable for large area films of high quality with effective material use and high deposition rate. In this context, this chapter discusses the recent developments in CIS and CIGS technologies using electrodeposition. In addition, the fundamental features of electrodeposition such as direct current, pulse and pulse-reverse plating and their application in the fabrication of CIS and CIGS films are discussed. In conclusion, the chapter summarizes the utilization of pulse electrodeposition for fabrication of CIS and CIGS films while making a recommendation for exploring the group's unique pulse electroplating method.
Download or read book Defect Energies Band Alignments and Charge Carrier Recombination in Polycrystalline Cu In Ga Se S 2 Alloys written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work investigates the defect energies, band alignments, and charge carrier recombination in polycrystalline Cu(In1-xGax)(Se1-ySy)2 chalcopyrite thin films and the interrelationship with the alloy composition. Photoluminescence spectroscopy of investigated Cu-poor Cu(In, Ga)(Se, S)2 layers generally shows broad emission lines with the corresponding maxima shifting towards higher energies under decreasing temperature or under increasing excitation power. Admittance spectroscopy of Cu-poor ZnO/CdS/Cu(In, Ga)(Se, S)2 chalcopyrite devices shows that the activation energies of the dominant defect distributions involving donors at the CdS/absorber interface and deep acceptors in the chalcopyrite bulk, increase upon alloying CuInSe2 with S. The band alignments within the Cu(In1-xGax)(Se1-ySy)2 system are determined using the energy position of the bulk acceptor state as a reference. The band gap enlargement under Ga alloying is accommodated almost exclusively in the rise of the conduction band edge, whereas the increase of band gap upon alloying with S is shared between comparable valence and conduction band offsets. The extrapolated band discontinuities [delta]EV(CuInSe2/CuInS2) = -0.23 eV, [delta]EC(CuInSe2/CuInS2) = 0.21 eV, [delta]EV(CuInSe2/CuGaSe2) = 0.036 eV, and [delta]EC(CuInSe2/CuGaSe2) = 0.7 eV are in good agreement with theoretical predictions. Current-voltage analysis of Cu-poor ZnO/CdS/Cu(In, Ga)(Se, S)2 devices reveals recombination barriers which follow the band gap energy of the absorber irrespective of alloy composition, as expected for dominant recombination in the chalcopyrite bulk. In turn, the recombination at the active junction interface prevails in Cu-rich devices which display substantially smaller barriers when compared to the band gap energy of the absorber. The result indicates that the Cu-stoichiometry is the driving compositional parameter for the charge carrier recombination in the chalcopyrite heterojunctions under investigations.
Download or read book Characterization of Cu In Ga Se2 CIGS Films with Varying Gallium Ratios written by and published by . This book was released on 2015 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cu(In1-x, Gax)Se2 (CIGS) absorber layers were deposited on molybdenum (Mo) coated soda-lime glass substrates with varying Ga content (described as Ga/(In + Ga) ratios) with respect to depth. As the responsible mechanisms for the limitation of the performance of the CIGS solar cells with high Ga contents are not well understood, the goal of this work was to investigate different properties of CIGS absorber films with Ga/(In + Ga) ratios varied between 0.29 and 0.41 (as determined by X-ray florescence spectroscopy (XRF)) in order to better understand the role that the Ga content has on film quality. The Ga grading in the CIGS layer has the effect causing a higher band gap toward the surface and Mo contact while the band gap in the middle of the CIGS layer is lower. Also, a wider and larger Ga/(In + Ga) grading dip located deeper in the CIGS absorber layers tend to produce larger grains in the regions of the films that have lower Ga/(In + Ga) ratios. Moreover, it was found that surface roughness decreases from 51.2 nm to 41.0 nm with increasing Ga/(In + Ga) ratios. Furthermore, the surface roughness generally decreases if the Ga grading occurs deeper in the absorber layer.
Download or read book Local Built in Potential on Grain Boundary of Cu In Ga Se2 Thin Films written by R. Noufi and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a direct measurement of two-dimensional potential distribution on the surface of Cu(In, Ga)Se2 (CIGS) thin films using a nanoscale electrical characterization of scanning Kelvin probe microscopy (SKPM). The potential measurement reveals a higher surface potential or a smaller work function on grain boundaries (GBs) of the film than on the grain surfaces. This demonstrates the existence of a local built-in potential on GBs and that the GB is positively charged. The role of the built-in potential in device performance was further examined by tuning Ga content or band gap of the film. With increasing Ga content, the GB potential drops sharply in a Ga range of 28%-38%. Comparing the change in the built-in potential to the theoretical and experimental photoconversion efficiencies, we conclude that the potential plays a significant role in the device conversion efficiency of NREL's three-stage CIGS device.
Download or read book Investigation of the Microstructure of Cu In Ga Se2 Thin Films Used in High Efficiency Devices Preprint written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This conference paper describes the microstructure of Cu(In,Ga)Se2 (CIGS) films, as it transitioned from Cu-rich to In-rich composition, by transmission electron microscopy, and energy-dispersive X-ray spectroscopy. We find that the Cu-rich samples have larger grains than the In-rich samples, and they contain two structurally different forms of the CuxSe secondary phase. These samples also showsub-interfaces about 0.2 ..mu..m below the surface. The In-rich samples were almost void of these sub-interfaces.
Download or read book Optimization of the Ga and S Diffusion Processes in Cu In Ga Se2 Thin Films written by Francis Birhanu Dejene and published by . This book was released on 2003 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
