Cadmium Sulfide/Copper Ternary Heterojunction Cell Research: Final Subcontract Report, 1 October 1984-31 May 1987

摘要

This is the final technical progress report on a thirty-two month research program on CuInSe sub 2 and CuInGaSe sub 2 based thin-film polycrystalline heterojunction solar cells. CuInGaSe sub 2 films incorporating Ga fractions (x in CuIn/sub 1-x/Ga/sub x/Se sub 2 ) from 0.04 to 1.0 have been prepared and characterized. CuInGaSe sub 2 /CdZnS heterojunction devices have been fabricated for a range of Ga contents and show the expected variations in Voc and spectral response with Ga content. An efficiency of 10.2% (SERI test, ASTM87) has been measured for a cell with Ga fraction of 0.23, the highest efficiency reported for this material. A CuInSe sub 2 /CdZnS monolithically interconnected four cell series string of 91 cm sup 2 area has been fabricated with a total area efficiency of 9.5% (SERI test, ASTM87). Results are presented on Ion-Assisted Deposition of the selenide and sulfide, on a new design for the Se evaporation source, on ITO reactive sputter deposition, and on CdZnS films prepared from an E-Gun Evaporation source. Spectral response and I-V characteristic variations with selenide composition before and after heat-treatment are discussed for the CuInSe sub 2 /CdZnS devices. The highest AM1 total area efficiency for the CuInSe sub 2 /CdZnS cell is now 11.9% (Boeing test, AM1 spectrum) with five cells measured over the previously reported high of 10.9%. Room Temperature Photoluminescence, Voltage Contrast Imaging of junction cross sections, Raman spectroscopy, and EXAFS measurements on the CuInSe sub 2 /CdZnS devices are also presented and discussed. 45 refs., 41 figs. (ERA citation 13:017976)