【作者】 岳磊；

【导师】 蔡伟；

【作者基本信息】 四川大学 ， 凝聚态物理， 2005， 硕士

【摘要】 二氧化锡（SnO₂）是一种宽带隙的金属氧化物。SnO₂ 薄膜具有可见光透过性强、紫外吸收系数大、有一定红外反射能力、化学性能稳定以及室温下抗酸碱能力强等优点。已经广泛应用于太阳电池、透明电极材料、气敏材料、光电材料以及电热材料等领域。本文依托863 计划“CdTe 薄膜太阳电池制造技术及中试生产线”,重点研究了SnO2薄膜在太阳电池上的作为透明高阻层（HRT）应用。CdTe 电池作为目前最有广泛应用前景的一种薄膜太阳电池,其材料制备上的研究已经开展的很普遍,为了进一步提高电池效率,已经开始在电池结构上寻求突破,如:在TCO 和CdS 之间加入透明高阻层（HRT）以及在CdTe 和背电极间加入重掺杂的过渡层。这些结构上的改变都极大的提高了CdTe 太阳电池的转换效率。而未掺杂的SnO₂薄膜由于它和广泛采用的前电极SnO2:F 是同一种物质,有着相同的功函数并且和CdS 层有良好的欧姆接触,所以是一种较为理想的HRT 过渡层材料。本文综合介绍了各种制备SnO₂薄膜的方法及优缺点,比较选择出PECVD法作为制备本征SnO₂薄膜的最佳方案。最终制备出做为HRT 过渡层使用的本征SnO₂薄膜,并进行了薄膜退火研究。用X 射线衍射仪（XRD）、紫外-可见光光谱仪（UV-Vis absorption Spectrometer）以及光电子能谱（XPS）等测试手段对制备出的薄膜进行结构和性能表征。结果表明:在200℃左右沉积出的SnO₂薄膜均为非晶态,但在400℃左右薄膜开始逐渐变为多晶态。不同的SnCl₄/O₂流量比对SnO₂薄膜的透过率影响明显,发现最佳的流量比值,并对其电导率变化的机制进行讨论最后,我们研究了HRT 在电池中的作用。分析了HRT 与SnO₂:F 界面势垒和HRT 与CdS 界面的点接触特性。并将PECVD 制备得到本征SnO₂薄膜用于CdTe 电池中,在其他各项工艺相同的情况下制备出有HRT 过渡层和无HRT过渡层的两组CdTe 太阳电池,以期进行对比。结果表明,拥有HRT 过渡层更多还原

【Abstract】 SnO₂ is a kind of wide bandgap materials, it has been widely applied in many fields such as solar cell, electric heating devices, transparent electrodes and gas sensors, due to its excellent properties, i.e. wide bandgap, high transparency in visible region, high stability. This thesis research the production of intrinsic SnO₂ film by PECVD and the application of this film on CdTe thin films solar cells as HRT buffer layer. This means which inserting a HRT buffer layer between the TCO and CdS has been proved that increasing the cells’efficiency more. Intrinsic SnO₂ film has not only the same work function with TCO but also the good ohmic contact with CdS film, so it can be used as a kind of HRT materials. In this paper, intrinsic SnO₂ films were successfully fabricated by PECVD and annealed in N₂/O₂ gas. The prepared films were characterized by X-ray diffraction, UV-Visibile absorption and XPS. It was found that intrinsic SnO₂ films were amorphous structure at 200℃and turned to the polycrystalline at 400℃. The high SnCl₄ content result in low transparent, on the other hand, it bring high conductance. Finally, the effect of HRT buffer layer in cells had been studied. As analyzed the result of HRT buffer layer effecting with SnO₂:F and CdS layer, the conclusion had been obtained, which was useful that electron moving through CdS layer to SnO₂:F layer. In the same manufacture process, two group of CdTe cells which one had HRT buffer layer and another had not HRT buffer layer were compared. The result was indicated that the cells which have HRT layer have better properties than other group, so its efficiency increased evidently. As for this experiment, the cells’efficiency with HRT buffer layer increase more 14.4% than the cells without HRT buffer layer.更多还原