Structural, Morphological, and Optical Properties of Single Step Electrodeposited Cu_2ZnSnS_4 (CZTS) Thin Films for PV Applications

摘要

Cu_2ZnSnS_4 (CZTS) is a promising compound for use as absorber in thin film solar cells. In this paper we report on the results of CZTS thin film grown on SnO_2/F coated glass substrates by co-electrodeposition at different applied potentials. The obtained thin films were sulfurized in N_2 atmosphere at 550°C for 1h. The structural, morphological and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption techniques. SEM analysis shows a very dense and uniform surface with large particles. X-ray diffraction patterns exhibit the kesterite structure of CZTS with the preferred orientation of the (112) plan and other kesterite peaks assigned to (002), (101), (110), (103),(200), (220), (224) and (400) planes. Raman spectroscopy measurements confirm the XRD results with clear peaks at 253, 289, 339 and 368 cm~(-1). The Raman shift was attributed to CZTS kesterite mode vibration. Finally, the bandgap of CZTS film is found to be close to 1,5eV.