【作者】 刘红娟；

【导师】 汪雷； 杨德仁；

【作者基本信息】 浙江大学 ， 材料科学与工程， 2010， 硕士

【摘要】 随着传统石化能源的日益减少,太阳能作为一种重要的可再生能源逐渐成为人们关注的热点。光伏发电是太阳能利用研究领域中最重要的发展方向之一。过去的几十年里,全球光伏产业发展迅速。目前占市场份额90%以上的是晶体硅太阳电池,由于其使用的原材料高纯硅价格较高,生产过程中能耗高,电池生产成本难以降低,阻碍了它的进一步大范围应用。近年来,薄膜太阳电池由于具有低成本、高性能等优点而引起了人们的广泛关注。CuInS₂和CulnSe₂（CIS）等Ⅰ-Ⅲ-Ⅵ₂族化合物薄膜电池具有高理论转换效率、直接禁带、高光吸收系数、禁带宽度与太阳光谱相匹配和稳定性好等优点,因此成为很有发展前景的下一代太阳电池。普遍采用的真空法制备此类CIS薄膜虽然成膜质量较好,但设备和技术要求都很高,导致成本较高。采用非真空法如喷涂,颗粒涂覆,电沉积等制备CIS薄膜设备简单,投资少,薄膜的生产成本低,而且容易大面积成膜,有望实现CIS薄膜太阳电池工业化大规模量产,具有很好的发展前景。采用电沉积法制备CIS薄膜易于控制薄膜的厚度,可在大尺寸和形状复杂的衬底上沉积薄膜,并且电沉积过程在室温下进行,能量损耗低。一步电沉积法与两步电沉积法相比,能同时将三种元素还原到衬底上,易于控制薄膜的成分,获得缺陷较少的高质量CIS薄膜。本文利用一步电沉积法制备了CuInS₂和CuInSe₂薄膜,对制备的薄膜进行了分析和表征,并初步制备了CuInS₂薄膜太阳电池原型器件。本论文取得的主要成果如下:1.利用一步电沉积法制备出具有不同Cu/In比的均匀致密的CuInS₂薄膜,薄膜的厚度约为1—2μm,薄膜为黄铜矿结构,禁带宽度约为1.47 eV,呈p型。研究了沉积电位、衬底、Cu/In比、pH值、柠檬酸钠用量和原材料等对先驱体薄膜的影响以及后续热处理条件对CulnS₂薄膜的影响。2.在一步电沉积法制备CuInS₂薄膜的基础上初步制备出结构为Mo/CuInS₂/CdS/ZnO/ITO/C的薄膜太阳电池原型器件。电池的平均开路电压为350mV,平均短路电流为3mA/cm²,填充因子为20%,最高转化效率为0.57%。3.利用一步电沉积法制备出均匀致密的CuInSe₂薄膜,薄膜的厚度约为1-2μm,黄铜矿结构。研究了沉积电位和衬底对先驱体薄膜的影响以及后续热处理条件对CuInSe₂薄膜的影响。更多还原

【Abstract】 With the increasing decrease of conventional fossil energy, solar energy, as one kind of significant renewable energy, has becoming a focus. The photovoltaic technology is one of the most important development aspects in the utilization field of solar energy. In the past decades, photovoltaic industry in the world developed rapidly. The further massive application of crystalline silicon solar cells, accounting for more than 90% of the world photovoltaic market at present, is prevented by the high production cost of solar cells due to the costly price of high purity silicon raw material and high energy consumption in the production process. Recently, thin film solar cells with the predominance of low cost and high performance have attracted much attention. I-III-VI2 family compound thin film cells such as CuInS₂ and CuInSe₂ （CIS）, with high theoretical photoelectric conversion efficiency, direct band gap, optimum width of band gap, extraordinarily high absorption coefficient and long-term stability, are considered promising candidates for next generation solar cells.Although generally vacuum deposition techniques fabricate high quality CIS thin films, the production cost is high due to vacuum equipments and rigorous techniques. Preparation of CIS thin films by non-vacuum deposition techniques such as spray, particle-coating and electrodeposition, with a good development foreground, needs inexpensive equipments and low investment capital. Not only the production cost of thin films is low, but also large-area preparation of CIS thin films is feasible. Large-scale industrialization of CIS thin film solar cells is promising to come true.The thickness of CIS thin films prepared by electrodeposition method is easy to control. Precursor thin films can be deposited on large size and complicated shape substrates. The electrodeposition process is at room temperature, so it consumes low energy. Three kinds of elements are reduced onto a substrate synchronously in one-step electrodeposition method, compared with two-step electrodeposition method. The composition of films can be controlled, and high quality films with few defects can be obtained. In this thesis, the CuInS₂ and CuInSe₂ thin films were prepared by one-step electrodeposition method. The precursor thin films and multicrystalline CIS thin films were analyzed and characterized. Moreover, the primary archetypal CuInS₂ thin film solar cell devices were fabricated.The following results have been obtained:1. Uniform and compact CuInS₂ thin films with different Cu/In ratio were prepared by one-step electrodeposition method. They’re p-type chalcopyrite semiconductors with direct band gap of about 1.47 eV and thickness of about 1～2μrn. The influences of applied potential, substrates, Cu/In ratio, pH value, the concentration of citric acid sodium and raw material in the precursor thin films and the effect of post anneal treatment conditions on multi-crystalline CuInS₂ thin films were studied.2. The CuInS₂ thin film solar cells with a configuration of Mo/CuInS₂/CdS/ZnO/ITO/C, fabricated on CuInS₂ thin films prepared by one-step elecrodeposition, take on the photovoltaic characteristic. The average values of V_oc, I_sc and FF are 350 mV, 3 mA/cm² and 20%, respectively. The highest conversion efficiency is 0.57%.3. Uniform and compact CuInSe2 thin films of chalcopyrite phase with a thickness of about 1～2μm were prepared by one-step electrodeposition method. The influences of applied potential and substrates in the precursor thin films and the effect of post anneal treatment conditions on multi-crystalline CuInSe2 thin films were studied.更多还原