电镀法在氧化铟锡上制备铜锌锡硫薄膜的光谱特征

低成本、环境友好的铜锌锡硫替代含贵金属和有毒金属的铜铟镓硒，是薄膜太阳能电池的最佳选择。电镀法是一种无需真空设备和靶材的低成本方法。一种更简单的制膜方法是在水溶液中共电镀沉积Cu-Zn-Sn（CZT)合金于FTO衬底上。采用氩气保护气氛下在550 ℃硫化电镀法制得的CZT合金前驱体，成功制备了CZTS薄膜。采用三电极体系将CZT合金前驱体电镀在FTO上，其中FTO作为工作电极，铂（Pt）网和Ag/AgCl分别作为对电极和参比电极。电解质由CuSO₄，ZnSO₄，SnSO₄，络合剂-三乙醇胺（TEA）和柠檬酸钠组成。前驱体在氩气保护气氛下550℃硫化得到CZTS薄膜。采用X射线衍射（XRD）、拉曼光谱、扫描电子显微镜（SEM）、紫外可见光光谱仪和光电化学测量（PEC）等方法，表征了CZTS薄膜的结构、形貌、成分和光谱学性质。XRD和拉曼光谱证明了550 ℃硫化后的CZTS薄膜具有锌黄锡矿结构。一个Raman主峰位于342 cm-1，两个Raman次强峰分别位于289和370 cm-1，这些峰位与锌黄锡矿CZTS的峰位相吻合。SEM结果证明优化后CZTS薄膜成分接近CZTS的理想化学计量比，CZTS薄膜中Cu/(Zn+Sn）和 S/(Zn+Sn+Cu)分别为0.52和1.01，这表明CZTS薄膜中S的含量非常合适。PEC结果证实，采用前照射或后照射FTO/CZTS均产生光电流，并且两种照射下产生的光电流方向一致。通过紫外可见光光谱测量并由此计算出的CZTS能隙为1.45 eV。通过上述分析证明制备的CZTS薄膜具有高品质，可用于制备CZTS薄膜太阳能电池。

Spectral Characterization of Electrodeposited Cu2ZnSnS4 Thin Films on Fluorine-Doped Tin Oxide

Low cost and environment friendly Cu₂ZnSnS₄ (CZTS) is the best candidate to replace CuIn_xGa_1-xSe₂ (CIGS) which owns noble and toxic metal for thin film solar cells. Electrodeposition technique is a low cost method where vacuum equipment and target materials are not required. A simpler fabrication method is co-electrodeposition of Cu-Zn-Sn (CZT) alloy on fluorine-doped tin oxide (FTO) in aqueous solution. In this paper, CZTS thin films were successfully prepared by sulfurization of electrodeposited CZT alloy precursors at 550oC in protective argon gas. The CZT precursors were electrodeposited on FTO via a three-electrode system in which FTO is used as working electrode, platinum (Pt) mesh and Ag/AgCl as counter and reference electrodes. The electrolyte contains CuSO₄, ZnSO₄, SnSO₄, complexing agent-Triethanolamine (TEA) and sodium citrate. The precursors were sulfurized by sulfur vapor at 550 ℃ in protective argon gas and then CZTS films were obtained. The structural, morphological, compositionaland optical properties of CZTS films have been characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-vis spectroscopy and photoelectrochemical measurement (PEC). XRD and Raman spectroscopy have confirmed the kesterite structure of CZTS films sulfurized at 550 ℃. One major peak at 342 cm-1 and two second strong peaks at 289 and 370 cm-1 are observed in the Raman spectra, which agree with those reported from kesterite CZTS. SEM shows chemical composition of optimum CZTS film is near that of stoichiometric CZTS. The ratios of Cu/(Zn+Sn) and S/(Zn+Sn+Cu) in CZTS film are 0.52 and 1.01, respectively, which indicates that the content of S in “copper poor” CZTS film is very suitable. The photocurrent of the “copper-poor” CZTS film was measured by PEC. PEC results confirm that light current is produced by FTO/CZTS under front/back irradiation, and the photocurrent flows in the same direction in both cases. The band gap of CZTS is 1.45 eV. It is shown that high-quality CZTS thin films have been prepared via above analysis.