Preparation Of CIGS Thin Film By The Pulsed Laser Deposition Method And Post-Selenization

In recent years, solar cell as the fastest growing clean energy has been developed rapidly with the character of no noise, no pollution, no geographical restrictions and low cost.The CuInGaSe2 (CIGS) thin film solar cells as the absorption layer was prepared on glass substrates or other low-cost six or more layers compound semiconductor or metal thin film materials. The total thickness was about 3-4μm.This kind of thin-film solar cells was called the most promising one of the cheap solar cells with its low cost, stable performance, strong resistance to radiation, high photoelectric conversion efficiency.The paper includes two aspects to research CIGS thin film solar cells.Firstly, the CIG prefabricated films with the different composition ratio were prepared by the method of pulsed laser deposition (PLD) and CIGS thin films were also prepared under the same conditions of selenide. Then, we has systematically studied the influence of the parameters as laser energy and the sputtering times on the structure and morphology of the films. Secondly, the CIG prefabricated films with the same composition ratio were prepared by PLD method and CIGS thin films were also prepared under the different conditions of selenide. Then, we has systematically studied the influence of the parameters as heat treatment temperature on the structure, morphology and optical properties of the films.The CIGS thin-film has been detected by level meter, X-ray diffraction (XRD) Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and UV spectrophotometer, the results show that the gathering phenomenon of In can be avoided with setting the target sputtering energy of CuGa and In as 350 and 250mJ, respectively. The target distance was 35 mm. We also found that the atomic concentration of Cu,Ga were 0.98 and 0.28, respectively under selenization when the target sputtering number of CuGa and In were five and six million times; the film thickness was 1.3μm and the particle has clear outline and uniform size when the selenium transition temperature was 250℃with seleniding 60 minutes and the heat treatment temperature was 550℃with heat-treating 30 minutes. The CIGS thin-film surface is very dense, low roughness and closely binding with the substrate. The best heat treatment temperature is 550℃when the film forming a single chalcopyrite structure and have excellent light absorption characteristics in the visible and infrared area.