铜铁锡硫（CFTS）薄膜的制备及性能表征

发布时间：2018-04-09 13:53

  本文选题：太阳能电池　切入点：Cu_2FeSnS_4　出处：《华东师范大学》2017年硕士论文

【摘要】：20世纪以来,随着不可再生能源的日益减少,可再生能源逐渐成为最具决定性影响的技术领域。由于太阳能清洁安全、取之不尽、用之不竭,因此对太阳能电池材料的研究引起了科学家们的广泛关注。其中,已商业化的Cu(In,Ga)(Se,S)2(CIGS)和CdTe吸收层材料虽然具有性能稳定、能量转换效率高(超过20%)等优点,已成为光伏领域的研究热点之一。但因其元素稀有且有毒,加之生产成本较高,限制了它们的大规模使用。最近,人们又将目光放在四元硫属化合物Cu2FeSnS4(CFTS)上,CFTS具有与CIGS相似的晶体结构,因其元素含量丰富无毒,且有良好的光电性能、合适的光学带隙(1.20 eV-1.50 eV)和较高的吸收系数(104 cm-10,被认为是另一种最具有潜力的太阳能电池吸收层材料。到目前为止,CFTS薄膜太阳能电池的最高转换效率为8.03%,与CIGS薄膜太阳能电池相比,还有相当大的提升空间,因此对CFTS薄膜进行研究有很好的发展前景。本文主要采用电化学沉积法在透明导电FTO衬底上沉积Cu2FeSnS4薄膜前驱体,然后硫化退火制备CFTS薄膜。通过实验寻找最佳的沉积CFTS薄膜的条件,并对结果进行分析研究。运用恒电位沉积法研究薄膜的制备条件,成功制备出了 CFTS薄膜。采用X射线衍射仪(XRD)、拉曼光谱仪(Raman)、X射线能谱仪(EDS)、X射线光电子能谱(XPS)、能谱仪元素像分析技术(Mapping)和紫外可见近红外分光光度计(UV-Vis-NIR Spectrophotometer)对薄膜的结构、元素组成及价态和光学性质进行了分析研究。研究结果表明:退火时间与退火温度对CFTS薄膜的生长情况、光学特性都有很大的影响。在N2气氛下,退火时间保持在30 min,退火温度为550℃时,制备出的CFTS薄膜结晶度最高,并且其禁带宽度最接近理论值,约为1.48 eV,可推断出,该方法制备出的CFTS薄膜材料满足太阳能电池器件制作的要求。其次,采用磁控溅射法在玻璃(SLG)衬底上设计并制备了 Cu-Fe-Sn金属层前驱体,并对其硫化退火形成CFTS薄膜。探究了最佳的沉积顺序、溅射条件以及退火条件。采用X射线衍射仪(XRD)、拉曼光谱仪(Raman)研究了薄膜的结构特征,通过扫描电子显微镜(SEM)和Mapping观测了薄膜的表面形貌及元素分布的均匀性,使用X射线光电子能谱(XPS)分析了薄膜中各元素的化学价态,采用紫外可见近红外分光光度计(UV-Vis-NIR Spectrophotometer)测量并计算了薄膜的光学带隙。研究发现：不同的溅射顺序对薄膜有很大的影响。当溅射顺序为Fe/Sn/Cu时,所制备薄膜的附着性最佳,不脱落。当在550℃条件下退火时,所制备薄膜的结晶度最高,且表面形貌最平整,各元素分布均匀,禁带宽度为1.47 eV,符合太阳能电池对吸收层材料带隙值的要求。
[Abstract]:Since the 20th century, with the decreasing of non-renewable energy, renewable energy has gradually become the most decisive technical field.Because solar energy is clean and safe, it is inexhaustible and inexhaustible, so the research of solar cell materials has attracted wide attention of scientists.Among them, the commercial CdTe and CdTe absorption layer materials have the advantages of stable performance and high energy conversion efficiency (over 20 parts), which have become one of the research hotspots in the field of photovoltaic.However, their rare and toxic elements and high production costs limit their large-scale use.Recently, attention has been paid to the tetrabasic sulfur compound Cu2FeSnS4CFTS, which has a crystal structure similar to that of CIGS, because of its rich element content, non-toxic, and good optoelectronic properties.The suitable optical band gap (1.20 eV-1.50 EV) and high absorption coefficient (104cm-10) are considered as another potential solar cell absorption layer material.So far, the highest conversion efficiency of CFTS thin film solar cells is 8.03. Compared with CIGS thin film solar cells, there is still considerable room for improvement. Therefore, the research on CFTS thin film has a good prospect.In this paper, the precursor of Cu2FeSnS4 thin films was deposited on transparent and conductive FTO substrates by electrochemical deposition, and then CFTS films were prepared by vulcanization annealing.The best conditions for deposition of CFTS thin films were found by experiments, and the results were analyzed and studied.The preparation conditions of CFTS thin films were studied by potentiostatic deposition, and the CFTS thin films were successfully prepared.The composition, valence state and optical properties of the elements were studied.The results show that annealing time and annealing temperature have great influence on the growth and optical properties of CFTS films.In N2 atmosphere, when annealing time is kept at 30 min and annealing temperature is 550 鈩，

本文编号：1726706