Raman spectra of CuInSe2 thin films prepared by chemical spray pyrolysis

Raman spectra have been investigated for CuInSe2 polycrystalline thin films prepared by chemical spray pyrolysis. The A(1) mode Raman peak at 174 cm(-1), the dominant peak in CuInSe2 with a chalcopyrite structure, and a peak at 182 cm(-1) have been observed. The A(1) mode peak is dominant for Cu-rich films and stoichiometric films deposited at high substrate temperature. On the other hand, the 182 cm(-1) peak is dominant for In-rich films and stoichiometric films deposited at low substrate temperature. By comparing the Raman results with the X-ray diffraction measurements, the peak at 182 cm(-1) is found to be characteristic of CuInSe2 with a sphalerite structure.