液相法制备铜锌锡硫硒薄膜及其光电性能研究

发布时间：2018-04-23 18:37

  本文选题：CZTSSe + 溶液法　； 参考：《河南大学》2015年硕士论文

【摘要】：Cu2ZnSnS4(CZTS)是用Zn、Sn替代CuInS2(CIS)半导体中的In演化形成的新型半导体材料,具有禁带宽度与太阳能最佳吸收禁带宽度相接近,吸收系数高(104cm-1),环境友好,且成本相对低廉的优点,得到学术研究者的大量关注。目前制备CZTS的方法主要有真空法和非真空法,真空法具有制备薄膜致密缺陷少的优点,但缺点是所用设备昂贵,能耗大,成为制约真空法大规模制备CZTS薄膜的主要原因。非真空法包括电沉积法、溶胶凝胶法、热注入法和溶液法。溶液法因不需要复杂的纳米晶合成过程,可以显著的降低成本。近年来出现的肼溶液法获得了基于铜锌锡硫硒(CZTSSe)制备的太阳能电池的最高效率,但肼存在剧毒、易燃易爆以及购买受限等缺点。针对肼溶液法中所存在的缺点,本文采用低毒、低成本的分子水平溶液(联氨和联硫醇的混合溶液)为溶剂,溶解金属硫属化合物,制备分子水平的前驱体溶液制备CZTSSe薄膜,并根据制备薄膜的特点及性质将其应用到太阳能薄膜电池和染料敏化电池中。本论文的工作主要包括以下几个部分:(1)用乙二胺为主要溶剂,制备CZTSSe前驱体溶液。在1200 rpm下旋涂三次即可形成厚度为1.5μm的CZTSSe薄膜,从XRD可以看出前驱体薄膜结晶性不好,通过退火处理得到结晶性良好的薄膜。通过硒化处理得到表面带有大晶粒的薄膜,这表明Se更有利于晶粒的生长。通过对比硒化前后薄膜的表面我们可以发现,硒化过程是原有小晶粒重新长大的过程。由于乙二胺具有强烈的挥发性,在空气环境下易生成盐类化合物,使预制膜表面疏松多孔,造成硒化之后薄膜连续性不好。(2)将得到的疏松多孔的CZTSSe薄膜,用于染料敏化太阳能电池中,并研究不同后处理对CZTSSe作为对电极对染料敏化太阳能电池性能的影响。发现S/S+Se≈0.5的CZTSSe薄膜,获得了最高的转化效率,其效率为6.13%,这与相同条件下Pt作为对电极取得6.20%的转换效率是相当的。(3)将相对稳定的二乙烯三胺引入到CZTSSe体系中,改变旋涂转速得到表面致密的前驱体薄膜,通过硒化处理得到表面致密且结晶性良好的薄膜,采用标准电池的制备方法,组装太阳能电池。最终我们组装完成了有效面积为0.19 cm2的电池,并进行了性能测试,该电池的转换效率为3.28%。
[Abstract]:Cu2ZnSnS4CZTS is a new type of semiconductor material, which is formed by replacing in evolution of CuInS2CCISS semiconductor with ZnSn-Sn. It has the advantages that the band gap is close to the best absorption band gap of solar energy, the absorption coefficient is high 104cm-1C ~ (-1), the environment is friendly, and the cost is relatively low. Get a lot of attention from academic researchers. At present, the main methods of preparing CZTS are vacuum method and non-vacuum method. Vacuum method has the advantages of less dense defects, but the disadvantages are that the equipment used is expensive and the energy consumption is large, which is the main reason that restricts the large-scale preparation of CZTS thin films by vacuum method. Non-vacuum methods include electrodeposition, sol-gel, thermal injection and solution. Solution method can significantly reduce the cost because it does not require complex nanocrystalline synthesis process. In recent years, hydrazine solution method has obtained the highest efficiency of solar cells based on copper, zinc, tin, sulfur and selenium (CZTSSee). However, hydrazine has some disadvantages, such as high toxicity, flammable and explosive, and limited purchase. In view of the disadvantages of hydrazine solution method, CZTSSe thin films were prepared by dissolving metal sulfur compounds in low toxicity and low cost molecular level solution (mixed solution of hydrazine and mercaptan). According to the characteristics and properties of the prepared thin films, they are applied to solar thin film cells and dye sensitized cells. The main work of this thesis includes the following parts: 1) preparing CZTSSe precursor solution with ethylenediamine as the main solvent. CZTSSe thin films with thickness of 1.5 渭 m can be formed by spin-coating at 1200 rpm for three times. It can be seen from XRD that the crystalline properties of the precursor films are not good, and the films with good crystallinity can be obtained by annealing. The thin films with large grains on the surface were obtained by se treatment, which indicates that se is more favorable to grain growth. By comparing the surface of the thin films before and after selenization, we can find that the process of selenization is the process of the original small grains growing again. Due to the strong volatility of ethylenediamine, it is easy to form salt compounds in the air environment, which makes the surface of the prefabricated membrane loose and porous, resulting in poor continuity of the film after selenization. The effect of different post-treatment on the performance of dye-sensitized solar cells using CZTSSe as electrode was studied. It was found that the highest conversion efficiency of CZTSSe films with S / S se 鈮，

本文编号：1793130