[13p-B9-1~11] New characterization technologies for functional properties of multinary compounds - new insight into development of multinary compound devices -

△ [13p-B9-9] Investigation of Cu-doping effects in CdTe solar cells using junction photoluminescence

〇Yasuyoshi Shiina¹, Shota Okamoto¹, Tamotsu Okamoto¹ (1.NIT, Kisarazu Coll.)

Keywords:CdTe, thin-film solar cells, II-VI compounds

Cu-doping effects in CdS/CdTe solar cells were investigated by photoluminescence (PL) of the CdS/CdTe junction using excitation lights incident on the glass substrate side (junction PL) with various excitation wavelengths. In the Cu-doped CdS/CdTe solar cells, broad emissions at 910-950 nm, which were probably caused to donor-acceptor pair (DAP) emission between Cu_Cd acceptors and Cl_Te donors, were observed. The intensity of the junction PL drastically increased due to the Cu doping. This result suggests that the intensity of junction PL is relevant to the conversion efficiency of CdTe solar cells. Furthermore, PL peak energy increased with increasing the excitation wavelength. This result indicates that CdS_xTe_1-x mixed crystal layer is formed in the CdS/CdTe interface, and that S composition decreased from the CdS/CdTe interface to the rear.