A deep semiconductor defect with continuously variable activation energy and capture cross section

A deep level with a continuously varying activation energy and capture cros s section has been observed in CdS/CdTe thin-film solar cells. Given that t he activation energy and capture cross section of a level are usually consi dered to be a unique identifier or signature for a particular deep level, t his has important implications for the application of deep-level transient spectroscopy and related techniques for the characterization of deep levels in this and similar systems. We believe this phenomenon explains the well- known but poorly understood efficacy of CdCl2 treatment for CdS/CdTe thin s olar cells. (C) 1999 American Institute of Physics. [S0003-6951(99)03328-8] .