PHOTOLUMINESCENCE STUDY 0 F HIGHLY EFFlCl E N T CdTe THllN FILM SOLAR CELLS

Highly efficient CdTe thin film solar cells with %I glass1 CdS I CdTe I Cu-doped carbon I Ag structure, were characterized by low temperature photoluminescence (PL) measurement. A broad 1.42eV band probably due to Vcd-CI defect complexes appeared as a result of the CdC12 treatment. In the PL spectra of the heat-treated CdTe after the screen-printing of the Cu-doped carbon paste, a neutral-acceptor bound exciton (A:", X) line at 1.590eV was observed, suggesting that Cu atoms were incorporated into CdTe as effective acceptors alter the heat treatment. Furthermore, CdSICdTe junction PL was measured, and two broad emissions at around 1.52 and 1.37eV, lower than the PL peak energy in the! CdTe surface, were observed. This result indicates that CdSI.,Tq, mixed crystal layer was formed at the CdS/CdTe interface.