【作者】 罗派峰；

【导师】 朱长飞；

【作者基本信息】 中国科学技术大学 ， 材料物理与化学， 2008， 博士

【摘要】 铜铟镓硒（Cu（In,Ga）Se₂,简写GIGS）薄膜太阳能电池以其转换效率高、成本低、性能稳定等优点,而引起国际光伏界的广泛关注。本文主要从高效、低成本以及环境友好等角度出发,研究电池器件中光吸收层和缓冲层等薄膜材料的真空和非真空制备工艺,以期为CIGS薄膜电池的大面积商业化应用奠定基础。论文主要分为三部分,具体内容如下:第一部分主要包括高质量CIS和CIGS薄膜的真空溅射后硒化工艺探索及其反应机理研究。首先,是CIS薄膜的射频溅射后硒化法制备。采用Cu靶和In靶依次溅射CuIn金属预置层,以Se粉取代剧毒H₂Se硒化,制备出了接近化学计量比的富铜CIS薄膜,对薄膜结构、形貌和电学性能进行了表征,得到了最佳的硒化温度500℃,并推断出CuSe与InSe在高温下化合生成CIS的反应路线。然后,是CIGS薄膜及器件的射频溅射后硒化法制备。根据高效电池的梯度带隙“三明治”结构设计,采用CuInGa合金靶和In靶交替溅射CuInGa金属预置层,并利用多步分层式硒化法,来降低硒化过程中Ga的偏聚和优化薄膜组分,制备出了高质量的CIGS薄膜及效率器件,得到4.67%的光电转换效率。最后,采用脉冲激光沉积（PLD）后硒化法制备CIS薄膜。利用PLD腔的较高真空度,对金属预置层进行低温合金化,硒化后制备出了符合化学计量比的CIS薄膜,吸收系数达到了10⁵cm^-1量级,光学带隙为0.98 eV,并证明了低温合金化工艺有利于CIS单相薄膜的形成。第二部分为CIS薄膜的低成本非真空法制备。首先,采用操作简单的电沉积工艺制备CIS薄膜。以导电玻璃（ITO）为衬底,采用恒电位共沉积的方法成功制备出了符合化学计量比的CIS薄膜,考察了沉积电位、溶液PH值、浓度配比、络合物以及退火工艺等因素的影响,并得出了电沉积CIS薄膜的最佳工艺:配比为Cu:In:Se=1:5:2,络合剂柠檬酸钠的浓度为0.1M/L,在PH值为1.7,电压为1.6V的条件下制备的CIS薄膜较好,退火后薄膜结晶性能大幅度提高。其次,采用同样合成简单、成本低廉的非真空旋涂工艺制备CIS薄膜及器件。分别以Cu-In和Cu-In-Se两种可溶性盐为前驱物,采用简单易操作的旋涂法制备CIS薄膜,探索出了单相性较好的CIS薄膜的非真空旋涂制备工艺,并研究了不同前驱物浆料对薄膜成相质量及性能的影响规律,结果说明Cu-In-Se前躯体更能制备出光滑平整的薄膜,并采用非真空法制备出了CIS效率电池,光电转换效率为0.97%。最后一部分为无毒环保型缓冲层材料ZnS薄膜的制备。首先,主要是采用操作简单的湿法化学浴和电沉积工艺制备ZnS薄膜,探索出了电沉积和化学浴法制备ZnS薄膜的最佳工艺:PH=3,U=0.1V,t=30min;T=80℃,t=15min,考察了退火工艺的影响,并通过各种表征手段对两种工艺进行了比较,对比得出采用电化学法明显优于传统CBD法的结论。其次,则主要想从干法的PLD工艺入手,开发全干法的CIGS制程工艺。在不同的沉积温度下制备出了高质量的ZnS薄膜,对薄膜进行了表征,对比湿法沉积的CdS工艺,具有成本低、无毒环保和更强短波段光吸收的优势,并有望在CIGS薄膜电池缓冲层材料的全干法制程工艺中得到应用。更多还原

【Abstract】 Copper indium gallium selenide（Cu（In,Ga）Se₂,abbreviated GIGS） thin film solar cells for its high conversion efficiency,low cost,stable performance,etc.,while having caused wide concern by the international photovoltaic industry.In order to establish the foundation for arge-scale commercial applications of CIGS solar cells, mainly from high-performance,low-cost and environmentally friendly,such as the point of view,the vacuum and non-vacuum preparation technologies of the absorption layer and buffer layer have been researched.Therefore,the thesis structure is also divided into three main parts,as follows:The first part mainly includes the exploring the preparation technology of high-performance CIS/CIGS thin-film solar cells by vacuum sputtering and selenization process,and study the reaction mechanism.First,the CIS thin films are prepared by RF sputtering and selenium.The CuIn metal layers are prepared by sputtering the Cu target and In target.In order to replace the highly toxic H₂Se,the selenium powder is used to selenide the CuIn metal layers.Nearly stoichiometric copper-rich CIS thin films are obtained.The film structure,morphology and electrical properties are characterized.The best selenide temperature 500℃is obtained,and inferred the reaction route of CIS is generated by the CuSe and InSe compound at a high temperature.Then CIGS thin films and devices are prepared by RF sputtering and selenium.In order to obtain the gradient bandgap "sandwich" structure of high performance cells,CuInGa metal layers are parpared through alternating sputtering CuInGa alloy target and In target.Taking advantage of multi-step hierarchical method of selenization,it reduces the process of segregation Ga.And the high-quality CIGS thin films are obtained,and the photoelectric conversion efficiency of CIGS thin-film devices is 4.67%.Finally,the CIS thin films are prepared by the pulsed laser deposition（PLD） and selenization.It uses the high vacuum of PLD chamber for the low-temperature alloy of the metal pre-layers.After selenization,the stoichiometry of the CIS thin films are obtained,absorption coefficient reaches a 10⁵ cm^-1 order of magnitude,optical band gap is 0.98 eV,which is the proof of low-temperature alloying process in favor of CIS single-phase formation.The second part is the CIS thin films prepared by low-cost non-vacuum methods. First of all,the use of simple electro-deposition preparation of CIS thin film technology.In this experiment conductive glass（ITO） is use as the substrates.Using potentiostatic deposition method are successfully prepared in line with the stoichiometry of the CIS thin films,and visited the deposition potential,solution PH value,the concentration ratio,as well as complex annealing process and other factors and concluded that the best technology of electrodeposition CIS thin film:ratio of Cu: In:Se=1:5:2,the concentration of complexing agent for sodium citrate 0.1M/L,in PH value of 1.7,voltage of 1.6V under the conditions of preparation of CIS thin film is better,the crystallization properties of annealed films increases.Secondly,the low cost non-vacuum spin-coating process is used to prepare the CIS thin-film devices. Respectively,Cu-In and Cu-In-Se two soluble salt as precursor,using a simple easy-to-use spin-coating of the CIS thin film,explored a single-phase nature of the better CIS thin films prepared by spin-coating of non-vacuum process,and to study different precursors of the film into a slurry with the quality and performance of law, results indicate that it can obtain better smooth thin-film used the Cu-In-Se precursors. Using non-vacuum method,solar cells devices efficiency obtains 0.97%.The last part is the preparation for the environment-friendly non-toxic buffer layer material ZnS Thin Films.First of all,the wet chemical bath and electro-deposition process are used to prepare ZnS thin film,and we explore the best technology of preparation ZnS thin film by electrodeposition and chemical bath routes: PH=3,U=0.1V,t=30min;T=80℃,t=15min,investigated the effects of annealing process,and through a variety of characterization by means of two processes are compared,and we conclude that the electrochemical method obviously superior to the traditional CBD method.Secondly,mainly want to develop the whole dry process of CIGS manufacturing.At different deposition temperatures the high-quality ZnS thin films are prepared,and films are characterized.Compareing to wet deposition technology of CdS films,it has many advantages,such as low cost, non-toxic environmental protection and more short-band optical absorption edge.It is expected to be applied in the whole dry process of manufacturing CIGS thin film cells.更多还原