热蒸发法制备SnS薄膜及其表征

Characterization of SnS Films Prepared by Thermal Evaporation

用热蒸发技术在ITO玻璃基片上沉积SnS薄膜.通过对该薄膜进行结构、成分和表面形貌分析,表明它是具有正交结构的SnS多晶薄膜;相对于恒电流电沉积法制备的SnS薄膜来说,该薄膜颗粒更细,粒径在(60～100) nm,并且它的均匀性和对基片的附着力也更好.通过测量薄膜样品的反射和透射光谱,得到其直接禁带宽度Eg=1.34 eV,在基本吸收边附近的吸收系数大于2×104 cm-1.该薄膜的导电类型为p型,电阻率的数量级为10-2 Ω·cm.因此,用热蒸发技术制备出的SnS薄膜的质量和性能都比较理想,该薄膜非常适合做太阳能电池的吸收层.

p-type SnS films were grown on ITD-film-coated glass substrates by themral evaporation. Its microstructures, composition and properties were characterized with X-my diffraction（XRD）, scanning electron microscopy（SEM） and optical measurement. The results show that the polycrystalline SnS film has an orthorhombic structure with the grain sizes ranging from 60 to 100 nm. The fairly uniform film strongly adheres to the ITO surface and its resistivity is of the order of 10^- 2 Ω· cm. Its direct band gap is estimated to be 1.34 eV with an absorption coefficient near the fundamental absorption edge larger than 2 × 10^4 cm^- 1. We suggest that the SnS film grown by thermal evaporation be good absorption material for solar cell fabrication.