High-performance supercapacitor electrode of Cu2ZnSnS4 (CZTS) thin films grown by ECD

In this paper, we studied the capacitive performance of a kesterite Cu2ZnSnS4 (CZTS) electrode grown on an ITO (indium tin oxide) substrate by an electrochemical deposition technique (ECD) at room temperature for the first time. It was then annealed at 580 degrees C for an hour in a N2 atmosphere with sulfur powder. The X-ray diffraction (XRD) analysis of the CZTS sample revealed it to have a tetragonal crystal structure, with characteristic peaks (2 2 0) and (1 1 2) corresponding to the kesterite phase. The Raman spectrum of CZTS thin films (TFs) displayed a prominent peak at around 324 cm-1. The surface morphology typically demonstrated that the growth was spread across the entire surface, with each region displaying similar, yet heterogeneous structures at varying depths. From cyclic voltammetry (CV), at a scan rate of 1 mV s-1, the specific capacitance value was determined as 1483 F g-1, while it was calculated as 73 F g-1 for a scan rate of 100 mV s-1. Also, from galvanostatic charge-discharge measurement, the specific capacitance value of an electrode comprising CZTS TFs was determined to be 1695 F g-1 at a current density of 1 A g-1, while this value was 277 F g-1 at a current density of 10 A g-1. It has been discovered that electrochemically produced CZTS TFs exhibit excellent supercapacitive performance.