纳米金属氧化物制备多晶Cu(In,Ga)Se2薄膜反应过程及其性能研究

摘要

以铜铟镓纳米金属氧化物为起始原料,采用化学还原+固体硒源后硒化的方法在不锈钢表面制备出多晶Cu(In,Ga)Se2(CIGS)薄膜.采用场发射扫描电镜、高分辨透射电镜、能谱分析和X射线衍射等方法对制备过程中材料组成和结构的演变进行了研究,采用霍尔效应测试仪和吸收光谱分析等对多晶CIGS薄膜的性能进行了表征.研究结果表明,纳米金属氧化物主要含CuO、In2O3、Ga2O3和铜-铟、铜-镓二元合金氧化物等成分,在还原反应中逐渐转变成Cu11In9、Cu9In4等产物,同时薄膜中形成大量孔隙；硒化过程中,硒蒸气沿孔隙通道进入还原产物的晶格,反应生成CIS和CGS,从而形成具有黄铜矿结构的多晶CIGS薄膜；多晶CIGS薄膜表面晶粒排列紧密,属于p型半导体,其载流子浓度为2.3×1015 cm-3,迁移率为217 cm2/(V.s),电阻率为36Ω·cm,带隙宽度约为1.15 eV.%Polycrystalline Cu(In,Ga)Se2(CIGS)thin film was prepared by non-vacuum method with nano-metal oxide as starting materials.The evolution of the composition and structure during the preparation process was investigated by field emission scanning electron microscope,high resolution transmission electron microscope,energy dispersive analysis and X-ray diffraction.The properties of CIGS film was characterized using Hall Effect tester and absorption spectroscopic analysis.The results show that the nano-metal oxide is consist of CuO,In2O3,Ga2O3 and copper-indium,copper-gallium binary alloy oxides.The metal oxides gradually transform into Cu11In9 and Cu9In4 during the reduction reaction.Moreover,it forms a large number of pores,which is benefit for the selenide reaction.The selenium vapors enter the film along the pore,react with the reduction product and form CIS and CGS in the selenide process.Then,the polycrystalline CIGS film with the chalcopyrite structure forms.The carrier concentration,mobility and the resistivity of CIGS film are about 2.3×1015 cm-3,217 cm2/(V.s)and 36 Ω·cm,respectively.The obtained thin film is a p-type semiconductor with a bandgap of about 1.15 eV.