STUDY OF THE INTERFACE CHANGES DURING OPERATION OF NCDTE-ELECTROLYTE SOLAR-CELLS

Previous work has shown that while nCdTe-electrolyte solar cells are low cost and efficient, their photocurrent decays after a few hours of operation. We ave systematically analyzed the changes that take place at the interface. Auger spectroscopy measurements have shown out-diffusion of Cd2+ and the formation of a Te layer at the surface. Electroreflectance (ER) and electroluminescence measurements have further shown that this process results in the formation of a p-type region. The evolution of the ER spectra as the p-type region develops was followed and fully analyzed. This technique offers the advantage of easy control and optimization of the p-n junction growth parameter. The influence of the Te layer on the cell performance was determined from spectral response measurements.