采用恒电位电沉积法在ITO上制备了铜铟镓硒(CIGS)前驱体薄膜, 该前驱体薄膜在充氩气管式炉中经过高温硒化可得到结晶良好的CIGS薄膜。 采用X-射线衍射(XRD)、 拉曼光谱(Raman)、 扫描电子显微镜(SEM)和紫外-可见光-近红外光谱仪分别表征了CIGS薄膜的结构、 形貌、 成分以及可见-近红外光谱(Vis-NIR)吸收特性。 XRD结果表明前驱体薄膜高温硒化后所得的CIGS薄膜具有(112)择优取向, 薄膜中CIGS晶粒的平均尺寸为24.7 nm, Raman光谱表明薄膜中的CIGS是具有黄铜矿结构的四元纯相, 没有其他二元三元杂相存在。 Vis-NIR测量结果表明CIGS的禁带宽度随薄膜中镓含量的增加而增加, 当Ga含量达5.41%时, 通过吸收光谱测得CIGS的禁带宽度为1.11 eV, 通过理论计算得到镓铟比为Ga/(In+Ga)=16.3%, 小于SEM测量所得的镓铟比Ga/(In+Ga)=21.4%, 这表明还需进一步提高CIGS薄膜的结晶度。 所有测量表明优化后的ITO/CIGS非常适合用来制作高质量的双面太阳能电池。 该研究提出了制备低成本CIGS前驱体薄膜及高温硒化的新方法, 通过这些方法在ITO上制备了均匀、 致密、 附着力好的CIGS薄膜。 通过上述表征可知, 在新工艺下制备的CIGS薄膜结晶度高, 成分合理, 无杂相, 光吸收性质好。 与磁控溅射法类似, 电沉积法非常适合大面积工业化生产, 该工作对CIGS的规模化生产具有重要的借鉴意义。

Cu(InxGa1-x)Se2(CIGS) precursor films were prepared on ITO glass with potentiostatic electrodeposition. High quality CIGS films were obtained by selenization of the precursor films at high temperature in tubular furnace full of argon gas. X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis-NIR spectroscopy were used to characterize the structure, morphology, composition and Vis-NIR absorption of CIGS films, respectively. XRD results show the selenized CIGS films have a preferential orientation (112) with average crystallite of 24.7 nm. Raman spectroscopy reveals that the CIGS films are pure quaternaryphases with chalcopyrite structure, and without binary or ternary phases in the films. Vis-NIR measurements determine that the bandgap of CIGS increases with the increase of Ga concentration in the film. When the Ga concentration is 5.41%, its bandgap is about 1.11 eV, and the calculated ratio of Ga to (Ga+In) is 16.3%, which is less than the ratio of Ga to (Ga+In), 21.4%, measured by SEM. This indicates that crystallinity of CIGS filmsneeds to be further improved. All the measurements demonstratethat optimum ITO/CIGS has a promising application in bifacial solar cells. In this paper, we provide a newmethodtoelectrodeposit low cost CIGS precursor films and a new method forselenization ofthe precursor films at high temperature. As a result, theuniform and compact CIGS films with good adhesion on ITO are successfully fabricated by these methods. The above characterization show that we have obtained CIGS films with high crystallinity, near stoichiometry, few impurity phases and superior light absorption. Electrodeposition, like magnetron sputtering, is very suitable for large-scale industrial production. The research work in this paper is therefore important and considerable to massive production of electrodeposition of CIGS films.