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Book Enhanced Quality Thin Film Cu In Ga Se sub 2 for Semiconductor Device Applications by Vapor phase Recrystallization

Download or read book Enhanced Quality Thin Film Cu In Ga Se sub 2 for Semiconductor Device Applications by Vapor phase Recrystallization written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Enhanced quality thin films of Cu.sub.w (In, Ga.sub.y)Se.sub.z for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In, Ga):Cu.sub.x Se on a substrate to form a large-grain precursor and then converting the excess Cu.sub.x Se to Cu(In, Ga)Se.sub. 2 by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In, Ga).sub.y Se.sub.z. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300.degree.-600.degree. C., where the Cu(In, Ga)Se.sub. 2 remains solid, while the excess Cu.sub.x Se is in a liquid flux. The characteristic of the resulting Cu.sub.w (In, Ga).sub.y Se.sub.z can be controlled by the temperature. Higher temperatures, such as 500.degree.-600.degree. C., result in a nearly stoichiometric Cu(In, Ga)Se.sub. 2, whereas lower temperatures, such as 300.degree.-400.degree. C., result in a more Cu-poor compound, such as the Cu.sub.z (In, Ga).sub. 4 Se.sub. 7 phase.

Book Official Gazette of the United States Patent and Trademark Office

Download or read book Official Gazette of the United States Patent and Trademark Office written by and published by . This book was released on 1994 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Recrystallization Method to Selenization of Thin film Cu In Ga Se sub 2 for Semiconductor Device Applications

Download or read book Recrystallization Method to Selenization of Thin film Cu In Ga Se sub 2 for Semiconductor Device Applications written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A process for fabricating slightly Cu-poor thin-films of Cu(In, Ga)Se.sub. 2 on a substrate for semiconductor device applications includes the steps of forming initially a slightly Cu-rich, phase separated, mixture of Cu(In, Ga)Se.sub. 2 :Cu.sub.x Se on the substrate in solid form followed by exposure of the Cu(In, Ga)Se.sub. 2 :Cu.sub.x Se solid mixture to an overpressure of Se vapor and (In, Ga) vapor for deposition on the Cu(In, Ga)Se.sub. 2 :Cu.sub.x Se solid mixture while simultaneously increasing the temperature of the solid mixture toward a recrystallization temperature (about 550.degree. C.) at which Cu(In, Ga)Se.sub. 2 is solid and Cu.sub.x Se is liquid. The (In, Ga) flux is terminated while the Se overpressure flux and the recrystallization temperature are maintained to recrystallize the Cu.sub.x Se with the (In, Ga) that was deposited during the temperature transition and with the Se vapor to form the thin-film of slightly Cu-poor Cu.sub.x (In, Ga).sub.y Se.sub.z. The initial Cu-rich, phase separated large grain mixture of Cu(In, Ga)Se.sub. 2 :Cu.sub.x Se can be made by sequentially depositing or co-depositing the metal precursors, Cu and (In, Ga), on the substrate at room temperature, ramping up the thin-film temperature in the presence of Se overpressure to a moderate anneal temperature (about 450.degree. C.) and holding that temperature and the Se overpressure for an annealing period. A nonselenizing, low temperature anneal at about 100.degree. C. can also be used to homogenize the precursors on the substrates before the selenizing, moderate temperature anneal.

Book Processing Approach Towards the Formation of Thin film Cu In Ga Se2

Download or read book Processing Approach Towards the Formation of Thin film Cu In Ga Se2 written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-stage method of producing thin-films of group IB-IIIA-VIA on a substrate for semiconductor device applications includes a first stage of depositing an amorphous group IB-IIIA-VIA precursor onto an unheated substrate, wherein the precursor contains all of the group IB and group IIIA constituents of the semiconductor thin-film to be produced in the stoichiometric amounts desired for the final product, and a second stage which involves subjecting the precursor to a short thermal treatment at 420.degree. C.-550.degree. C. in a vacuum or under an inert atmosphere to produce a single-phase, group IB-III-VIA film. Preferably the precursor also comprises the group VIA element in the stoichiometric amount desired for the final semiconductor thin-film. The group IB-IIIA-VIA semiconductor films may be, for example, Cu(In, Ga)(Se, S).sub. 2 mixed-metal chalcogenides. The resultant supported group IB-IIIA-VIA semiconductor film is suitable for use in photovoltaic applications.

Book Pulsed Electrochemical Deposition of CuInSe2 and Cu In Ga Se2 Semiconductor Thin Films

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.

Book Cu In Ga Se2 Thin Film Evolution During Growth A Photoluminescence Study Preprint

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.

Book Deposition of Single phase Cu In Ga Se2 Thin Films

Download or read book Deposition of Single phase Cu In Ga Se2 Thin Films written by Buyisiwe M. Mhlungu and published by . This book was released on 2004 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Compound Semiconductor Photovoltaics

Download or read book Compound Semiconductor Photovoltaics written by Materials Research Society. Meeting and published by . This book was released on 2003 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume focuses on basic and applied materials research related to compound semiconductors. Emphasis is on materials that are used, or have clear potential use, as thin films in solar cells and spin-off applications. Relevant materials include Cu(In, Ga, Al)(Se, S)2, MX (M = Zn and/or Cd; X = S, Se and/or Te), III-V photovoltaic materials, and transparent conducting oxides. Understanding fundamental materials limitations, real or perceived, are of particular interest. Highlights center on: materials-related prerequisites for high-efficiency thin-film solar cells; the dynamics of chemical treatment/etching of CdTe with emphasis on back contacting; high-resolution microanalysis of grain boundaries and surface chemistry and how they affect device performance; the role and significance of transparent conducting oxides in device performance; and the electronic structure of highly mismatched III-V alloy semiconductors.

Book Electrical Electronics Abstracts

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Processing Approach Towards the Formation of Thin Film Cu In Ga Se2

Download or read book Processing Approach Towards the Formation of Thin Film Cu In Ga Se2 written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Investigation of the Microstructure of Cu In Ga Se2 Thin Films Used in High Efficiency Devices Preprint

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.

Book Local Built in Potential on Grain Boundary of Cu In Ga Se2 Thin Films

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.