Influence of annealing temperature on the properties and solar cell performance of Cu2SnS3 (CTS) thin film prepared using sputtering method

Highly crystallized Cu2SnS3 (CTS) thin films are synthesized by sputtering based deposition route. Further, Influence of different annealing temperatures on crystallographic, electrical and optical properties of CTS thin films have been investigated. The synthesized CTS thin films are grown as a monoclinic structure observed from X-ray diffraction (XRD) of (112), (220), and (312) plane and it is further confirmed using Raman spectroscopy by the presence of Raman peaks at 295 and 354 cm(-1). The direct band gap energy of CTS thin film annealed at 580 degrees C is found to be 1.03 eV by extrapolation from external quantum efficiency (EQE) measurement. An X-ray photoelectron spectroscopy (XPS) study suggests that the ionic states of Cu, Sn, and S are Cu+, Sn4+, and S2+, respectively. The CTS based thin film solar cells (TFSCs) are fabricated with a structure of Mo/CTS/CdS/i-ZnO/AZO/Al. The preliminary power conversion efficiency of 1.35% with a short circuit current density of 28.3 mA/cm(2), an open circuit voltage of 147.5 mV, and a fill factor of 32% were obtained, although the processing parameters have not yet been optimized. (C) 2016 Elsevier B.V. All rights reserved.