Formation pathway of CuInSe₂ through solvothermal route

CuInSe₂ (CIS) is a promising material for thin film solar cell applications. In this work, CIS powders have been synthesized by solvothermal route at different reaction time. X-ray diffraction patterns and Raman spectra of the products reveal that the optimal reaction time is 36 h at 200 °C in order to obtain pure CIS phase. SEM images show an irregular morphology of synthesized CIS material. The formation pathway of CIS has also been studied. Cu-Se compounds are formed at the beginning of the reaction, which act as an important intermediate for the formation of CIS products. This result is not consistent with the reported mechanism.