Annealing Time Dependence of Crystallization in Cu2ZnSnSe4 Films

Abstract

Cu2 ZnSnSe4 (CZTSe) films were formulated by the selenization of Cu(Zn, Sn) (CZT) metal precursors. The CZT precursor was prepared by depositing zinc onto a Cu-Sn layer co-sputtered on molybdenum-coated soda-lime glass substrates. Selenium was evaporated thermally onto the CZT precursor. The resulting CZTSe film was then annealed at 450 °C for various annealing times (1, 3, 5, 10 and 15 min) using a rapid thermal process (RTP). Crystallization of the CZTSe film as a function of the annealing time was observed by X-ray diffraction (XRD). The XRD patterns of the films annealed over 3 min were well matched to those of a CZTSe single crystal. The lattice parameters of the CZTSe films annealed over 5 min were a = 5.639 Å and c = 11.356 Å. These values were reasonably close to the lattice parameters of a single crystal of Cu2 ZnSnSe4 (a = 5.693 Å and c = 11.333 Å). The energy gap of the CZTSe films was 1.14 eV. © 2013 Copyright Taylor and Francis Group, LLC.