Study On The Preparation Of Cu2Znsns4Thin Films By Pulsed Laser Deposition

Cu2ZnSnS4(CZTS) is a direct bandgap semiconductor material with a bandgap of1.5eV, a high visible light absorption coefficient up to104cm-1, and a theoretical photoelectric conversion efficiency around30%, and is considered as an attractive cheap film solar cells material with great application potential. In this thesis, CZTS thin films were fabricated by pulsed laser deposition under different substrate temperature and pulse laser energy. The specimens were characterized by various techniques such as X-ray diffraction, scanning electron microscopy and atomic force microscope. The effect of deposition conditions on the quality of the CZTS thin film was then discussed. The main results are as follows:1. The effect of substrate temperature and pulse energy on the crystallization of the films is as follows:Within a certain range, high substrate temperature and high pulse energy are conducive to the crystallization of the thin films. The films are inclined to show (112) preferred orientation within the substrate temperature range of300℃～500℃and the pulse energy range of130mJ～165mJ. And the films are inclined to show (220) preferred orientation within the substrate temperature range of200℃～250℃and the pulse energy range of180mJ～200mJ.2. The effect of substrate temperature and pulse energy on the grain size and surface morphology of the thin films is as follows:The grain size and surface roughness increased with the increase of substrate temperature and the pulse energy. However, the surface roughness will show a decreasing tendency as the pulse energy is higher than165mJ.3. The film deposition process was optimized based on the analysis of test results and (112) preferred oriented CZTS thin films with good quality were successfully prepared at300℃with the pulse energy of165mJ.