Published online by Cambridge University Press: 11 June 2013
CuInS2 thin films have been successfully prepared on Pyrex substrates using spray pyrolysis technique. In this work, we study the effect of the flow rate on the physical properties of CuInS2 thin films. X-ray diffraction pattern reveals the presence of tetragonal structure with (1 1 2) preferential orientation for CIS thin layers. Optical analysis by means of transmission T(λ) and reflection R(λ) measurements allows to determine the direct band gap energy value in the order of 1.44 eV, indicating that CuInS2 compound has absorbing properties favorable for applications in solar cell devices. Photoluminescence measurements are performed on CuInS2 crystals and the analysis reveals that the emission is mainly due to donor-acceptor pair transitions.