| 초록 |
Solar cells are some of the most promising energy production devices due to their eco-friendly power generation and lack of fuel cost. Thus, solar cells have been studied by many researchers and industries. And tin monosulfide (SnS) is a promising absorber layer material in solar cell devices. In addition to its outstanding electrical and optical properties, SnS does not contain rare heavy-metal atoms. Thus, many researchers have focused on fabricating highly efficient SnS-based solar cell devices. However, the effect of H2 annealing on thermally evaporated SnS thin films and their transfer characteristics with various metals have not been thoroughly studied yet. In this work, SnS was deposited by thermal evaporation using SnS powder and annealed in a H2 gas ambient at 400 ◦C. X-ray diffraction (XRD) and atomic force microscopy (AFM) confirmed that SnS thin films were well deposited on various metal electrodes. Scanning electron microscopy (SEM) revealing that particles were evenly distributed on Si substrates with continuous network. Hall measurements showed that electrical properties were improved after post-annealing in a H2 ambient. In Rutherford backscattering spectrometry (RBS), we obtained the atomic ratio between S and Sn using RUMP simulations. S and Sn atoms existed in an almost stochiometric amount (S:Sn = 0.95:1). These results revealed that our SnS thin films were single-phase with enhanced physical and electrical properties. Furthermore, the electrical band structure of SnS was investigated by UV-visible and ultraviolet photoelectron spectroscopy (UPS) analyses to predict the electrical band alignment when in contact with Ti, W, and Mo electrodes and finally, SnS with Mo and W electrodes showed the most conductive transfer characteristics. |
