Effect of thermal pretreatment of metal precursor on the properties of Cu_2ZnSnS_4 films

摘要

Zn/Sn/Cu(CZT) stacks were prepared by RF magnetron sputtering. The stacks were pretreated at different temperatures(200°C, 300°C, 350°C, and 400°C) for 0.5 h and then followed by sulfurization at 500°C for 2 h. Then,the structures, morphologies, and optical properties of the as-obtained Cu2 Zn Sn S4(CZTS) films were studied by x-ray diffraction(XRD), Raman spectroscopy, UV–Vis–NIR, scanning electron microscope(SEM), and energy-dispersive x-ray spectroscopy(EDX). The XRD and Raman spectroscopy results indicated that the sample pretreated at 350°C had no secondary phase and good crystallization. At the same time, SEM confirmed that it had large and dense grains. According to the UV–Vis–NIR spectrum, the sample had an absorption coefficient larger than 104cm-1in the visible light range and a band gap close to 1.5 e V.