Optical study of the influence of CdCl2 in large area CdS thin films grown by RF-sputtering

Abstract We present the results obtained by photomodulation (PM) at room temperature of semiconductor CdS thin films grown in large area (450 cm 2 ). The thin films were deposited on conducting glass (SnO 2 :F 7 Ω/□) by radio frequency-planar magnetron sputtering with a substrate temperature ( T s ) of 250 °C, an Argon pressure of 20 mTorr, a radio frequency power of 300 W and with a deposition time ( t d ) of 60 min. A thermal treatment with CdCl 2 in these thin films at different annealing times was carried out. In general the PM spectra show a better crystal quality in the CdS thin films annealed with CdCl 2 , which is corroborated with atomic force microscopy (AFM) and observed in the efficiency of the solar cells processed with these films.