Low temperature photoluminescence spectroscopy of thin film, polycrystalline CdTe/CdS solar cell structures

As-grown n-CdTe/n-CdS solar cell structures deposited on tin oxide-coated g lass have been studied using low temperature photoluminescence spectroscopy . The structures were annealed in air at temperatures up to 600 degreesC. F or anneal temperatures of 400-450 degreesC, and above, acceptor related tra nsitions at around 1.45, 1.51 and 1.56 eV are tentatively ascribed to coppe r, oxygen and V-Cd-related centres, respectively. Illuminated current-volta ge measurements have shown that these findings are consistent with consider able improvements in short circuit current density that are believed to be associated with n- to p-type conversion of the CdTe film.