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1、xx 大学毕业论文I毕毕 业业 论论 文文题题 目目 有机强碱溶液体系电沉积 CdTe 薄膜及相关机制研究 xx 大学毕业论文II摘 要CdTe 薄膜太阳电池是以 p 型的 CdTe 和 n 型的 CdS 的异质结为基础的太阳电池。CdTe 薄膜的禁带宽度为 1.45eV，吸收波长为 855nm，与太阳光谱非常匹配；具有很高的光吸收系数，在可见光范围内高达 104cm-1，2m 厚的碲化镉薄膜能吸收 99%以上的太阳光；同时还具有高的转换效率，其理论光电转换率高达 30。本实验采用电化学沉积法制备 CdTe 薄膜，主要研究有机强碱溶液中电沉积 CdTe 薄膜机理及其影响因素。本实验采用循环伏安
2、法来探究碲化镉薄膜的沉积机理，同时通过对有机碱性溶液的循环伏安曲线分析，探究 pH、温度、Cd2+浓度和 NTA 和 Cd2+络合比对沉积过程的影响。通过循环伏安曲线分析可知，较低的 pH 促进 TeO32-在CdS 薄膜表面进行吸附，有利于 CdTe 的沉积，能使 CdS 与 CdTe 的接触更加良好；由于反应为欠电位沉积，较高的温度能为反应提供足够的能量，但过高的温度会使 CdTe 薄膜的结晶度改变，使 CdTe 结晶度更好，电阻率降低，利于接下来的沉积；高浓度的 Cd2+对 TeO32-的吸附有抑制作用，同时 Cd2+浓度过高时，会使溶液中存在自由 Cd2+，高温下大量水解会降低 pH；
3、浓度过高或过低的NTA 都不利于沉积 CdTe 薄膜,会导致 CdTe 薄膜中 Te 过量或 Cd 过量。通过 X射线衍射仪、场发射扫描电子显微镜、X 射线能量分散谱仪等仪器对沉积的CdTe 薄膜进行表征，得出络合比为 8:1 时，CdTe 薄膜结晶度最好，取向为立方的（111），同时碲镉原子比与化学计量比最为接近，但 CdS 与 CdTe 接触面不良，接触面最佳的络合比为 16:1。xx 大学毕业论文III关键词：CdTe 薄膜太阳电池；有机碱性溶液；电化学沉积；沉积机理；络合比xx 大学毕业论文IVABSTRACTCdTe thin film solar cells are based o
4、n p-type CdTe and n-type CdS heterojunction-based solar cells.The band gap of CdTe film is 1.45eV, the absorption wavelength is 855nm, which matches the solar spectrum very well.With a high light absorption coefficient, in the visible range up to 104cm-1,2m thick cadmium telluride film can absorb mo
5、re than 99% of the sun;But also has a high conversion efficiency, the theoretical photoelectric conversion rate as high as 30%.In this experiment, CdTe thin films were prepared by electrochemical deposition. The mechanism of electrodeposited CdTe films in organic alkali solution was studied.In this
6、study, cyclic voltammetry was used to investigate the deposition mechanism of cadmium telluride thin films. At the same time, the cyclic voltammetry curves of organic alkaline solutions，The effects of pH, temperature, Cd2+ concentration and NTA and Cd2+ complexation on the deposition process were in
7、vestigated.By cyclic voltammetry analysis, it can be seen that the lower pH promotes the adsorption of TeO32- on the surface of CdS film, which is favorable for the deposition of CdTe, which makes the contact of CdS and CdTe better.Since the reaction is underpotential deposition, the higher temperat
8、ure can provide sufficient energy for the reaction,But the high temperature will make CdTe film crystallinity change, so that CdTe better crystallinity, resistivity is reduced, which is conducive to the next deposition;High concentration of Cd2+ on the adsorption of TeO32- inhibition, and Cd2+ conce
9、ntration is too high, the solution will exist free Cd2+, high temperature hydrolysis will reduce the pH;Excessive or too low concentration of NTA is not conducive to the deposition of CdTe film, will lead to CdTe thin film too much or Cd excess.The deposited CdTe films were characterized by X-ray di
10、ffraction, field emission scanning electron microscopy and X-ray energy dispersive spectroscopy.When the complexing ratio is 8: 1, the crystallinity of CdTe film is the best, the orientation is cubic (111), and the atomic ratio of cadmium tellurium is the closest to stoichiometric ratio, However, th
11、e contact surface between CdS and CdTe is poor, and the optimal ratio of contact is 16: 1.xx 大学毕业论文VKey words：CdTe thin film solar cells; Organic alkaline solution; Electrochemical deposition; Deposition mechanism;Complex ratioxx 大学毕业论文VI目 录摘 要.IABSTRACT .II目 录.III1 前言.11.1 太阳能电池发展历程.11.2 太阳能电池分类.21.2.1 晶体硅电池.21.2.2 薄膜电池.31.3 太阳能电池工作原理.41.4 碲化镉（CdTe）薄膜太阳能电池.61.4.1 碲化镉薄膜太阳电池研究进展.61.4.2 碲化镉薄膜的性质.61.4.3 碲化镉薄膜电池的结构.71.4.4 碲化镉薄膜太阳电池制备方法.81.5 选题的目的及研究内容.101.5.1 研究目的.101.5.2 研究内容.
