Electrical bistability of sol-gel derived Cu2ZnSnS4 thin films

Kesterite type CZTS (Cu2ZnSnS4) thin films were deposited on Indium Tin Oxide (ITO) coated glass substrates by simple sol-gel method. X-ray diffraction (XRD) pattern showed the presence of crystalline kesterite phase, whereas the electron microscopic (FESEM) analysis established the 1D morphology of the CZTS films. Electrical studies revealed the interesting bistability phenomena of CZTS films. The current-voltage (I-V) characteristics showed two distinct paths for forward and reverse sweep directions. Conducting AFM (C-AFM) studies also supported the bistability phenomena of the CZTS films. Present study on electrical bi-stability of the CZTS thin films will help to understand the defects in the absorber materials and the photovoltaic performance of the CZTS device.