ABSTRACT
This chapter examines the experimental results emerging for gallium arsenide (GaAs)-based solar cells to date. Fermi-level pinning at several discrete levels at metal/n-cadmium telluride (CdTe) interfaces sheds light on new understanding of the cadmium sulphate/cadmium telluride (CdS/CdTe) solar cells. This was made possible purely by the careful observation of experimental results. The appearance of discrete potential barriers and well-defined groups of open circuit voltages are the key observations that led to the new understanding. These results were first published in 2002 for CdS/CdTe solar cells, and a similar behaviour for copper indium gallium diselenide solar cells was revealed in 2009. The effects of defects on solar cell characteristics show how defect levels affect GaAs-based solar cells.
