Thermal effects in CuInTe2/CdS/ITO heterojunctions

CuInTe2 thin films and heterojunctions with CdS were grown, using a close-spaced vapor transport technique. These heterojunctions show a weak photovoltaic effect (open circuit photovoltage: ∼ 30 mV) which increases up to ∼ 200 mV when the junction temperature increases up to 90 C. Then the photovoltage decreases if the temperature is increased above 100 C. This phenomenon is reversible, and the photovoltage is very sensitive to the junction temperature. X-ray and electron microprobe studies showed us that the CuInTe2 films are in fact very deficient in copper and formed of at least two phases: CuInTe2 and In2Te3. We obtained similar results with films grown from CuIn(Se, Te)2, CuGaTe2, and CuGa(Se, Te)2 materials. (orig.)