CHARACTERIZATION OF THERMAL EVAPORATION ALUMINUM DOPED TIN SULFIDE THIN FILM

Abstract

Tin sulfide (SnS) has caught attention as alternative material for solar cell absorber layer. This is due to the abundant amount of Tin sulfide in nature and lower cost compared to other absorber layer materials such as copper indium gallium selenide (CIGS) and cadmium telluride (CdTe). The high absorption coefficient (α >104 cm-1) and ideal bandgap (in the range of 1.2 – 1.5 eV) made Tin sulfide a promising candidate for the absorber layer. The aims of this research is to introduce aluminum as dopant to optimize the structural and optical properties of the tin sulfide thin film. The variation of the weight percentage and annealing process is analyzed. The thin films are characterized by using X-ray diffraction (XRD) and UV- Visible Spectroscopy (UV-Vis Spectroscopy). All samples were orthorhombic SnS with preferred (111) and (101) crystallites orientation. With the increasing of aluminum doping concentration and annealing process, the average crystallite size increased from 16nm – 57nm. The evaluated energy band gap Eg of the Al:SnS films decreases from 1.49eV to 1.32eV. It is found that doping percentage and annealing process play vital roles in producing high quality and suitable absorber layer.