Prospect for Sn_mSb_(2n)S_(3n+m) (n = 1, m = 1, 2, 3) sulfosalt compounds

摘要

In an effort to prepare thin films of novel semiconductor materials that contain only cost effective, abundant, and relatively less-toxic materials, Sn_mSb_(2n) S_(3n+m) (n = 1, m = 1,2,3) ingots sulfosalts materials were successfully grown via horizontal Bridgman method using high-purity tin, antimony and sulphur elements. Crushed powders of these ingots were used as raw materials for the vacuum thermal evaporation. So, SnSb_2S_4, Sn_2Sb_2S_5 and Sn_3Sb_2S_6 thin films were deposited by single source vacuum evaporation onto non-heated glass substrates. Their structure, composition and morphology are studied by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), atomic force microscopy, Raman scattering and optical measurements. XRD patterns show that poly-crystalline Sn_mSb_(2n)S_(3n+m) thin films were obtained without heating the substrates. Optical measurements indicated a direct band gap in the range 1.47-1.63 eV and a strong absorption coefficient between 10~4 and 2.10~5 cm~(-1).