Properties of pulse electrodeposited copper gallium sulphide films

Copper gallium sulphide films were deposited for the first time by the pulse electrodeposition technique at different duty cycles in the range of 6–50 % at room temperature and at a constant current density of 1.0 mA cm^?2. The films exhibited single phase copper gallium sulphide. The grain size increased from 30 to 70 nm with increase of duty cycle. Optical band gap of the films varied in the range of 2.30–2.36 eV. The resistivity increased from 0.10 to 1.70 ohm cm with increase of duty cycle from 6 to 50 %. Preliminary studies on solar cells with p-CuGaS₂/n-CuInS₂ junction yielded an efficiency of 4.14 %. This is the first report on solar cells using CuGaS₂ with CuInS₂.