The most effective way to promote the PV industry is to improve the efficiency of solar cells. Increasing optical utilization and spectral absorption can improve the efficiency of wide-spectrum thin film solar cells. In the former period, the main research contents of this project are focus on how to widen the optical transmittances, obtain high haze values and increase the optical utilization in the long wavelength region. Some typical research results are listed as follows:(1)Properties of high valence difference WZO have been investigated by means of plane wave pseudo-potential method based on the DFT and pulsed DC magnetron sputtering technique. The theoretical and practical results show that the Fermi level enters into the conduction band when doping W atoms into ZnO, indicating a typical n-type semiconductor characteristic and the optical band gap Eg increases significantly.(2) Influences of indium doping on the electrical, structural and optical properties of ZnO films prepared by ultrasonic spray pyrolysis have been investigated. Experimental results show that indium dopant can enhance the carrier mobility and (001) preferential orientation of ZnO thin films, which make the ZnO:In thin films more conductive and strong light-scattering.(3) The structural, electrical and optical properties of LPCVD-ZnO:B thin films have been ameliorated through using the ZnO buffer layer. The experimental results show that the "rich oxygen" buffer layer effectively increased the near infrared optical transmittance.(4) A double-period structure to improve light absorption and trapping has been proposed by combining MS ZnO and LPCVD-grown ZnO:B films. This kind of mutiscale-tpye ZnO films as front electrodes are preliminarily used in tandem solar cells.(5)A high-performance ZnO electrode with high conductivity, transmittance and haze radio has been prepared by magnetron sputtering and post wet-etching. Effective textured surface with large crater and small crater compound is detected which enhance the long and short wavelength light trapping efficiency synchronously. Using this ZnO as front contact, an a-Si:H/a-SiGe:H/μc-Si:H triple tandem solar cell was obtained with an efficiency of 14.06%.(6)Cubic PbS QDs have been synthesized by chemical bath deposition. The effects of the reaction conditions on the properties of PbS QDs are investigated in detail. Specific technical approaches have been achieved to enhance the performances of upconverter with PbS QDs.%高效率太阳电池的获得是推动光伏产业得到进一步拓展的关键之一，如何充分利用太阳光，提高太阳电池的光谱吸收是提高电池效率的有效手段之一。透明导电窗口层材料作为薄膜太阳电池中的一层重要功能材料，其对太阳电池有源层的光吸收具有非常重要的作用。该研究前期围绕着如何拓宽太阳光的宽谱透过、高的绒度散射、以及长波长光的利用等方面进行了详细的研究，部分研究成果如下：(1)采用基于密度泛函理论的平面波赝势方法对W掺杂ZnO材料进行了理论分析，并采用磁控溅射技术进行了WZO薄膜的实验研究，理论与实验结果表明，W能够在ZnO中起到施主作用，获得n型半导体特性，同时能带简并效应使其光学带隙展宽；(2）研究了低成本超生喷雾技术制备ZnO工艺中In掺杂量对IZO薄膜特性影响的研究：In的掺入能有效提高ZnO薄膜的载流子迁移率，从而降低薄膜的电阻率，同时In的掺入具有抑制（002）晶面生长，促进（101）晶面生长的作用，使其具有良好的陷光效果；(3)通过优化ZnO缓冲层（buffer layer），有效地改善了LPCVD-ZnO：B的光电特性。结果表明“：富氧”的缓冲层有效地增加了ZnO：B-TCO的近红外区域透过率，使其更适应宽光谱薄膜太阳电池的发展要求；(4）提出了一类基于磁控溅射及LPCVD技术的具有复合陷光结构的ZnO前电极材料，并在叠层薄膜太阳电池中进行初步应用；(5）基于复合陷光结构的优势，采用磁控溅射技术，通过对沉积条件的有效控制以及后湿法腐蚀工艺的优化，获得了大坑、小坑兼有的高绒度的ZnO透明导电薄膜，将其应用于非晶硅/非晶硅锗/微晶硅三结电池中，初始效率达到了14.06%；(6)采用化学水浴法制备了PbS量子点材料，并对反应条件对样品的影响进行了系统的研究，确定了将PbS等IV-VI族化合物半导体量子点用于上转换器的具体技术途径。
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