【作者】 孙保平；

【导师】 庞山； 杜祖亮；

【作者基本信息】 河南大学 ， 凝聚态物理， 2012， 硕士

【摘要】 随着社会的进步、经济的发展，人们对能源需量求越来越多，而不可再生能源的枯竭以及对环境造成的污染与破坏已经成为21世纪主要问题之一。将太阳能转换成电能是解决能源枯竭和地球环境污染等问题的一个最好、最直接和最有效的方法之一。在各种类型的太阳电池中，Cu(In_1-xGa_x)Se₂（CIGS）太阳电池已经成为目前光伏领域中的研究热点。CIGS是一种Ⅰ-Ⅲ-Ⅵ族四元化合物直接带隙的半导体材料，黄铜矿的晶体结构。其禁带宽度可以在1.04－1.67eV范围内调整，可见光吸收系数高达105cm-1数量级。CIGS薄膜太阳电池因具有转换效率高、性能稳定、可薄膜化和低成本等优点而最有可能实现商业化生产的第三代太阳电池。制备低成本、高质量和大面积的CIGS吸收层是实现CIGS太阳电池的商业化生产的关键所在。在众多的制备方法中，电化学沉积法制备CIGS薄膜具有成本低、可实现大面积制备、原材料利用率高和制备系统稳定性好等优点而受到广泛关注，具有良好的应用发展潜力。本论文利用一步电化学法制备了CIGS薄膜，在此基础上通过化学水浴制备了CdS缓冲层。研究了沉积条件对CIGS形貌结构的影响，并且利用表面光伏技术研究了CIGS薄膜以及CIS/CdS薄膜的光电特性。首先以氯化铜，三氯化铟，三氯化镓，亚硒酸以及氨基磺酸和邻苯二甲酸氢钾做为缓冲剂的水溶液做为电解液，添加缓冲剂氨基磺酸和邻苯二甲酸氢钾，调节溶液pH值避免了沉积过程中氢气的产生，利用一步电化学法在FTO玻璃基底上沉积出CIGS薄膜。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）、电子能谱仪（EDS）对样品表征，结果发现电解液pH值为2.0，退火温度为500℃时，制备的CIGS薄膜形貌结构、结晶效果最为理想。同时采用表面光伏技术，研究了不同化学计量比对CIGS薄膜中光电荷动力学过程，其中化学计量比Ga/（In+Ga）约为0.3时，表面光伏最强，光电性能最好。其次通过在CIS薄膜上利用化学水浴法沉积了CdS过渡层，利用表面光伏技术研究了CdS/CIS界面电荷传输过程，结果发现：通过HCl溶液处理去掉CdS过渡层后的CIS薄膜的光伏强度明显增加。EDS结果发现CIS薄膜中Cu元素含量较少并且存在Cd元素，这可能是由于在沉积CdS过程中，部分Cd元素通过扩散进入CIS薄膜内部代替了Cu元素形成CdCu施主，促使CdS/CIS表面反型，改善了CIS表面缺陷，促进了光生电子-空穴对的分离。更多还原

【Abstract】 Along with social progress, economic development, energy demand higher and higher,while the depletion of non-renewable energy and the environment caused by pollution anddestruction has became one of the main problems of the21st century. The use of solar cellsdirectly convert solar energy into electrical energy is to solve the problems of energydepletion and the earth and environmental pollution is one of the best, one of the most directand most effective way. Various types of solar cells from Cu (In_1-xGa_x)Se₂（CIGS） as absorblayer of solar cells to become a research hotspot in the field of photovoltaic. CIGS is aI-III-VI family compound semiconductor materials, has a crystal structure of chalcopyrite. Itsband gap can be adjusted within the1.04-1.67range, with a direct band gap, and visible lightabsorption coefficient of up to105cm-1order of magnitude. CIGS thin film solar cell withhigh conversion efficiency, stable performance, low cost and so on become the mostpromising third-generation solar cell to achieve commercial production of solar cells. The keyis how low-cost preparation of large area, high-quality solar cells, the key part of the CIGSabsorber layer can achieve the commercial production of CIGS solar cells. CIGS thin filmprepared by electrodeposition method can achieve the preparation of large area, low prices,preparation of high efficiency, good stability of the preparation system, which has beenextensively studied, with a wide range of application development prospects. Our team hasprepared CIGS thin films by one step electrodeposition using a constant voltage, and thedeposition conditions and preparation of CIGS thin film optical and electrical properties wereanalyzed.In this paper, we make copper chloride, indium trichloride, gallium trichloride, seleniousacid as electrolyte, amino acid and potassium hydrogen phthalate as a buffer aqueous solution, CIGS thin films were deposited on the FTO glass substrate by one step electrochemicalmethod in a constant potential.The CIGS films were selenide annealed to improve thecrystallinity of the film and optimize the stoichiometry. By X-ray diffraction （XRD）, scanningelectron microscope （SEM）, energy dispersive spectroscopy （EDS）, and surface photovoltagespectrometer to sudy the characterization of the samples. From adjustting the pH value byadding the buffer amino acid and potassium hydrogen phthalate, we can avoid the generationof hydrogen in the deposition process. We conduct research and analysis prepared by one stepelectrodeposition of CIGS conditions and influencing factors.When the pH is2.0of theelectrolyte, annealing temperature is500°C, the crystallization effect and photoelectricproperties is best ideal.Finally, we deposit CdS thin films on the CIS thin-film by chemical bath deposition（CBD）, then remove the CdS thin films by hydrochloric acid. We use surface photovoltagespectroscopy （SPS） to study the CIS thin film surface photovoltage changes before and afterdepositing CdS thin films. The results showed that CdS thin films can enhance separationefficiency of the CIS thin films. We use the EDS to study the composition of CIS thin-filmbefore and after depositting CdS thin films. The results showed that we can find Cd elementin CIS thin film after remove the CdS, we think that this phenomenon is in the process ofdeposition of CdS, some Cd elements enter inside the CIS thin film by diffusion instead ofCu, to become CdCudonor, promote the CdS/CIS surface anti-type improve the CISsurface defects, to promote the photoinduced electron-hole pair separation, so that the opticaland electrical properties of CIS thin-film obtain enhancement.更多还原