Abstract

The phases, morphology and band gap of CuInS₂ films with wurtzite structure prepared by spin-coating and chemical co-reduction method were studied. Experimental results show that, CuInS₂ films with wurtzite structure can be prepared by using nitrates at low temperatures below 220 °C. When the anhydrous ethanol is used as the solvent, CuInS₂ film samples prepared with the sulfur powder as the sulfur source, the prepared CuInS₂ film has a wurtzite structure with poor crystallinity. When the other solvents such as ethylenediamine and ethanolamine were used, the CuInS₂ films prepared by using thiourea as the sulfur source also have the wurtzite structure. The product film with sulfur powder consists of a number of irregular particles with diameters between 0.3 and 0.5 μm, while the product films with thiourea consist of a number of flaky crystals and small spherical particles. The band gaps of the CuInS₂ films were estimated by extrapolation method. The estimated band gap of the wurtzite CuInS₂ film prepared by sulfur powder as sulfur source is about 1.45 eV, which is close to the theoretical value.

摘要

研究了旋涂和化学共还原法制备的具有纤锌矿结构的CuInS ₂薄膜的物相、形貌和带隙。实验结果表明，在低于220℃的低温下，使用硝酸盐可以制备具有纤锌矿结构的CuInS ₂薄膜。以无水乙醇为溶剂，以硫粉为硫源制备的CuInS ₂薄膜样品，制备的CuInS ₂薄膜具有纤锌矿结构，结晶度较差。当使用乙二胺和乙醇胺等其他溶剂时，CuInS ₂以硫脲为硫源制备的薄膜也具有纤锌矿结构。含硫粉的产品膜由许多直径在0.3-0.5μm之间的不规则颗粒组成，而含硫脲的产品膜由许多片状晶体和小球状颗粒组成。CuInS ₂膜的带隙通过外推法估计。以硫粉为硫源制备的纤锌矿CuInS ₂薄膜的估计带隙约为1.45 eV，接近理论值。