Cross-sectional, spectroscopic cathodoluminlscence studies of the ZNTE:Cu contact process for CDS/CDTE solar cells

Cross-sectional spectroscopic cathodoluminescence (CL), light current-voltage (LIV), and capacitance-voltage (CV) measurements are used to study the formation of CdS/CdTe devices contacted using ion-beam milling and sputter deposition of ZnTe:Cu/Ti layers. Prior to contacting, CL reveals significant differences in radiative recombination due to the purity of the CdCl2, source of device material, and the thickness of the CdTe. After contacting, differences in LIV and CV are correlated to CdTe thickness. These differences Support other studies that indicate diffusion from the contact assists in device formation. Although more subtle, differences in radiative recombination are also observed after contacting and suggest separate effects from Cl and Cu diffusion from the CdCl2 and contacting process.