Development of CuInTe2 thin film solar cells by electrochemical route with low temperature (80 °C) heat treatment procedure

• Temperature, 80 °C is sufficient to produce highly crystalline CuInTe2 thin films.
• Stoichiometric, uniform and well adherent thin films of CuInTe2 were electrodeposited.
• 3.8% efficiency was measured for a cell prepared by successive heat treatment at 80 °C.
• ‘Rs’ and ‘n’ investigated for Cell A and B were 47, 43 Ω and 2.0 and 1.9, respectively.

The effect of successive low-temperature heat treatment on the properties of electrodeposited CuInTe2 (CIT) thin films is investigated. The electrodeposition potential, −0.8 V versus Ag/AgCl was optimized by cyclic voltammetry onto CdS coated Fluorine doped tin oxide substrate. The samples were successively heat treated at 80 °C for 5, 30 and 60 min in an air ambient. The structural, morphological, compositional, electrical and optoelectronic properties were studied using XRD, Raman spectroscopy, SEM, FESEM, EDS, Current–Voltage and Capacitance–Voltage measurements. As-prepared CIT film exhibited amorphous nature, whereas the systematic development in the crystallinity was observed in successively heat treated samples. Compact, densely packed, globular surface morphology was observed. The Cu/In ratio was found to be increased systematically from 0.60 to 0.82 with heat treatment duration. The solar cell devices successively heat treated at 80 °C for 30 and 60 min measured an efficiency (η), 3.4% and 3.8%, respectively.

Dark and illuminated J–V characteristic for Cell B, successively heat treated at 80 °C for 60 min and corresponding dV/d(J + JL) versus 1/(J + JL) plot. Efficiency, η = 3.8%, series resistance, Rs = 43 Ω and ideality factor, n = 1.9 are measured for Cell B.Figure optionsDownload as PowerPoint slide