ABSTRACT
Fermi-level pinning at five discrete levels at metal/n-CdTe interfaces
sheds light on new understanding of the CdS/CdTe solar cells. This
wasmade 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 [1], and a similar behaviour for
CIGS solar cells was revealed in 2009 [2]. This short chapter briefly
examines the experimental results emerging for GaAs-based solar
cells to date.