碲化镉靶材制备及镀膜工艺研究

发布时间：2018-03-31 13:37

  本文选题：薄膜太阳能电池材料　切入点：CdTe靶材　出处：《北京有色金属研究总院》2014年硕士论文

【摘要】：CdTe禁带宽度为1.46eV,光谱响应与太阳光谱十分吻合,光吸收系数高达10-5cm-1,理论光电转换效率达到29%,是公认高效、廉洁的薄膜太阳能电池吸收材料。随着CdTe薄膜太阳能电池技术的发展,高效、适用于大面积的溅射镀膜工艺逐渐成为CdTe薄膜制备的主要方法,国内外对溅射镀膜工艺进行了大量的研究。溅射靶材作为镀膜的原材料,对薄膜的性能起着决定性的作用。出于技术保密,各国对该产品制备技术却鲜见报道。因此CdTe靶材的制备技术研究,对国内CdTe靶材及CdTe薄膜太阳能电池产业化发展有着重要的意义。 本文以真空熔炼后CdTe块材为原料,经破碎至300μm后,使用球磨机研磨CdTe粉体。通过研究研磨气氛、研磨时间对CdTe粉体粒度、纯度、物相结构、显微形貌的影响确立了CdTe粉体最佳研磨时间为10h,获得的粉体粒度在3-4μm,杂质元素含量在75ppm以下的高纯CdTe粉体。 以制备的CdTe粉体为原料,设计正交实验,采用热压烧结技术制备CdTe靶材。利用阿基米德排水法、XRD、SEM、ICP-MS等分析手段对CdTe靶材的致密度、相结构、组织形貌、纯度等性能进行表征。通过对正交实验结果进行极差分析,影响CdTe靶材致密度因素的工艺参数主次顺序为：保温时间、烧结温度、烧结压力；方差分析结果表明,在560℃-580℃温度范围内,保温时间、压力的改变对靶材密度的影响显著,烧结温度的改变对其影响微小。确定了热压制备CdTe靶材最优工艺参数：烧结温度580℃、保温时间60min、烧结压力33MPa。在最优工艺条件下制备CdTe靶材,靶材致密度达到99.4%,通过对靶材断面形貌进行观察,发现其晶粒尺寸比较均匀,靶材致密度非常好,仅含有微量封闭气孔。 分别以致密度97.7%的靶材和最优工艺条件下制备的致密度99.4%的靶材为溅射源,利用射频磁控溅射法沉积CdTe薄膜。通过对比薄膜的沉积速率、物相结构、光吸收系数、电阻率,发现致密度99.4%的CdTe靶材制备的薄膜各方面性能均要优于致密度97.7%靶材制备的薄膜。分别将沉积的非晶态CdTe薄膜在150℃、250℃、350℃真空退火1个小时,发现薄膜由非晶态结构转变为面心立方结构,且随着退火温度的升高薄膜电阻率急剧下降。 通过本文研究,建立了CdTe薄膜太阳能电池用靶材的热压制备工艺,采用射频溅射镀膜实验对靶材及其所得薄膜的性能进行考察,结果显示所制备的靶材可以满足制备薄膜太阳电池吸收材料的需要,为该材料的工业化生产和使用提供了研究基础。
[Abstract]:The band gap of CdTe is 1.46 EV, the spectral response is in good agreement with the solar spectrum, the optical absorption coefficient is as high as 10 ~ (-5) cm ~ (-1) and the theoretical photoelectric conversion efficiency is up to 29, which is recognized as a highly efficient and clean absorption material for thin film solar cells.With the development of CdTe thin film solar cell technology and high efficiency, the sputtering process suitable for large area sputtering has become the main method for the preparation of CdTe thin film. A lot of research on sputtering coating technology has been carried out at home and abroad.Sputtering target, as the raw material of coating, plays a decisive role in the properties of the film.Due to technical secrecy, the preparation technology of this product is rarely reported in many countries.Therefore, the research on the preparation technology of CdTe target is of great significance to the development of domestic CdTe target and CdTe thin film solar cell industrialization.In this paper, CdTe powder was ground by ball mill after crushing to 300 渭 m using vacuum melting CdTe block as raw material.By studying the effects of grinding atmosphere, grinding time on the particle size, purity, phase structure and microstructure of CdTe powder, the optimum grinding time of CdTe powder is 10 h, the particle size of CdTe powder is 3-4 渭 m, and the content of impurity element is below 75ppm.Using the prepared CdTe powder as raw material, orthogonal experiment was designed to prepare CdTe target by hot pressing sintering technology.The density, phase structure, microstructure and purity of CdTe target were characterized by Archimedes drainage method.Through the range analysis of the orthogonal experiment results, the order of the technological parameters influencing the density of CdTe target is as follows: holding time, sintering temperature, sintering pressure, variance analysis results show that, in the temperature range of 560 鈩，

本文编号：1690968