(One-step) electrochemical deposition and characterization of CuInSe2 thin films

Copper indium diselenide CIS (CuInSe2) thin films are prepared using electrochemical potentiostatic deposition technique (one step). The concentrations of SeO2 are (2.5 M, 3.75 M and 5 M), deposition potential is (−500, −600 mV) (SCE) and deposition temperature (25, 40 °C). The parameters for high-quality and homogeneity of CuInSe2 thin films fabrication are: deposition time 1.5 h and SeO2 concentration 3.75 M. CIS was deposited on sputtered Mo thin film as a back contact on glass substrate. High concentration of citric acid (100 M) was used in the bath solution. CIS thin films were characterized using XRD, EDAX, SEM and FTIR. Broadened diffraction peaks of CIS prepared at {25 °C, −500 mV (SCE)} were obtained in XRD, while its crystallinity was enhanced after heat treatment process. On the other hand, directly formation at {40 °C, −600 mV}, in addition, obtaining new planes of CIS after heat treatment. Notice, improvement of absorption peak of CIS at range 2345.28–2857.67 cm−1, corresponding to (Cu–Se2–In) by applying FTIR test at {T = 40 °C, V = −600 mV SCE}. As a result of changing deposition conditions, layer thickness of CIS increased from 0.799 to 1.979 μm and, the particle size of CIS decreased from 32 to 25 nm