Impact of Annealing Temperature on the Phase of CZTS with the Variation in Surface Morphological Changes and Extraction of Optical Bandgap

Abstract

Quaternary CZTS (Cu2ZnSnS4) is an emerging alternative semiconductor material for solar cell technologies due to its earth abundancy, low cost and non-toxic nature. In addition, CZTS has a direct band gap of ∼1.5 eV which is the optimal value for converting the maximum amount of energy from the solar spectrum into electricity. The aim of the present study is to investigate the impacts of annealing temperature on the phase formation and morphological behavior of CZTS and material optical characteristics. X-ray Diffraction (XRD) reveals the single phase of kesterite CZTS that has been grown from the material precursors. Scanning electron microscope (SEM) shows the variation of morphological changes of CZTS with respect to annealing temperature. UV-Vis analysis confirms the optical band gap of 1.5 eV in the visible region which is suitable for photovoltaic applications.