Hole traps in p-type electrochemically deposited CdTe thin films

Deep level transient spectroscopy and photoluminescence measurements were performed for the first time on electrodeposited n-CdS/p-CdTe thin film solar cells. The observed levels were hole traps located at 0.2, 0.35, and 0.54 eV above the valence band. The nature of these hole traps can be attributed to the generation of Cd vacancies during the heat treatment step, which was used in device fabrication, to convert the as-deposited n-type films into p-type layers.