热处理温度对CuInS2粉体物相、形貌及光吸收性能的影响

采用溶剂热法在不同反应体系和温度下,制备了一系列Cu In S2(CIS)粉体。CIS粉体的物相、形貌、光吸收性能分别用X射线衍射(XRD)仪、场发射扫描电镜(FESEM)、透射电镜(TEM)、紫外-可见光谱仪(UV-Vis)等手段进行了表征。结果表明,180℃时乙醇-硫脲体系所得"绣球"状CIS粉体为黄铜矿结构,而乙二胺-硫化钠体系则为"花簇"状纤锌矿结构,升高溶剂热温度,两者形貌均往"球体"演变;结合XRD,差热(DSC)分析表明纤锌矿CIS具有往黄铜矿CIS转变的趋势,物相转变温度约为453℃;受物相转变影响,纤锌矿CIS的带隙值由黄铜矿的1.43 e V减小至1.35 e V,其可见光吸收能力增强。同时探讨了CIS物相的转变机理。

Effect of Heat-Treatment Temperature on the Phase, Morphology and Optical Absorption Property of CuInS2 Powders

A series of CuInS2 (CIS) powders were prepared by changing the reaction system and temperature, via a facile solvothermal route. The phase, morphology and light absorption performance were characterized by XRD, FESEM, TEM and UV-Vis. It is found that the hydrangea-like chalcopyrite CIS and flower-like wurtzite CIS powders can be fabricated in ethanol-thiourea and ethylenediamine-Na2S·9H2O systems, respectively at 180 oC, and both of their morphologies can evolve to sphere structure after increasing the solvothermal temperature. DSC analysis, together with XRD, reveals a phase transition from wurtzite-CIS to chalcopyrite-CIS with the transition temperature standing at about 453 oC. Compared with chalcopyrite-CIS, the band gap of wurtzite-CIS decreases from 1.43 eV to 1.35 eV, and the visible light absorption property is correspondingly enhanced due to the phase transition. Additionally, the mechanism of CIS phase transition was also discussed