Structure and properties of CIGS films based on one-stage RF-sputtering process at low substrate temperature

Abstract

Currently, Nanjing South Railway Station planning to implement slate roof renovation is integrating solar cell modules into traditional roof materials to generate clean energy. Copper–indium–gallium diselenide (CuIn1−xGa x Se2, CIGS) is one of the most promising materials for thin film solar cells. Cu(In1−xGa x )Se2 films were deposited by a one-step radio frequency magnetron sputtering process at low substrate temperature. X-ray diffraction, Raman, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electrical and optical measurements were carried out to investigate the deposited films. The results reveal that a temperature of 320 °C is critical for near-stoichiometric CIGS films with uniform surface morphology. Cu-rich phase particulates are found at less than this temperature. The sample deposited at 380 °C gives well-crystalline single-phase CIGS film. Furthermore, the electrical and optical performances of the absorber layer are improved significantly with the increasing substrate temperature.