CuSbS₂ thin films by heating Sb₂S₃/Cu layers for PV applications

Abstract

In this work, we present the preparation of CuSbS₂ thin films of approximately 850 nm in thickness by heating glass/Sb₂S₃/Cu layers in low vacuum and their application in PV structures: Glass/SnO₂:F/n-CdS/p-CuSbS₂/C/Ag. The Sb₂S₃ thin films were chemically deposited from a solution containing SbCl₃ and Na₂S₂O₃ at 40 °C on well cleaned substrates. Copper thin films of 50 nm were thermally evaporated on Sb₂S₃ films of thickness ~600 and 800 nm and the glass/Sb₂S₃/Cu precursor layers were heated in vacuum at 300 and 350 °C for 1 h. Structural, morphological, optical and electrical characterizations of the annealed thin films were analyzed by X-ray diffraction, Atomic force microscopy, UV–Vis spectrometry and photoresponse measurements. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. Photovoltaic devices were prepared using CuSbS₂ thin films as absorber and chemical bath deposited CdS thin films as window layer on FTO coated glass substrates. The photovoltaic parameters of the devices were evaluated from the corresponding J–V curves, yielding J_sc, V_oc and FF values in the range of 1.03–1.55 mA/cm², 250–294 mV and 0.46–0.57 respectively, performed using a solar simulator under illumination of AM1.5 radiation.