摘 要

有机金属卤化物钙钛矿太阳能电池是一种全固态的钙钛矿结构作为吸光层的太阳能电池，具有制造成本低廉，带隙合适等优点，但同时具有稳定性差，含有毒元素Pb等缺点。目前三维钙钛矿太阳能电池的效率达到20%，而二维钙钛矿太阳能电池更加稳定但最高的效率仅仅只达到10%左右。

本文针对一种稳定性良好的二维钙钛矿薄膜材料(CH₃(CH₂)₃NH₃)₂(CH₃NH₃)₃Pb₃I₁₀进行了制备条件的优化。探究了三种不同的薄膜制备工艺过程。第一种为旋涂之后将玻璃片/钙钛矿分别在室温，90℃，120℃，150℃，180℃下退火15min。第二种为旋涂前将玻璃片分别在室温，90℃，120℃，150℃，180℃下加热，旋涂后不退火。第三种为旋涂前将玻璃片分别在室温，90℃，120℃，150℃，180℃下加热，旋涂后在100℃下加热退火15min。经过光学显微镜图片观察分析最后得出通过第三种工艺过程，可以得到形貌良好的钙钛矿薄膜材料，针对制备出的钙钛矿薄膜材料，进行了太阳能电池器件的组装。对第三种工艺做出的钙钛矿薄膜进行了表征及性能测试。通过扫描电子显微镜（scanning electron microscopy, SEM）可以看出钙钛矿晶粒的尺寸大概在34nm左右，薄膜的厚度大概在2μm。通过X射线衍射（X-ray diffraction, XRD）测试可以看到在(111)，(222)晶面处具有最强的XRD衍射峰。通过光致发光谱（photolumilescence, PL）和紫外可见吸收光谱（UV-Visible absorption spectrum，UV-VIS）测试表明这种钙钛矿材料的光学带隙在2.0eV左右，并且随温度的改变带隙有轻微偏移。采用第三种工艺在90℃和180℃热旋涂条件下制得的钙钛矿薄膜进行了太阳能电池器件的组装，组装的器件结构为掺杂氟的SnO₂透明导电玻璃（FTO导电玻璃）/致密TiO₂/介孔TiO₂/钙钛矿材料/ Spiro-OMeTAD（2,2',7,7'-四[N,N-二(4-甲氧基苯基)氨基]-9,9'-螺二芴）/Au。测试了它们的光电转换性能，结果表明180℃热旋涂的二维钙钛矿太阳能电池的能量转换效率PCE=2.42%，开路电压V_oc=0.837V，短路电流密度J_sc=9.09mA/cm²，填充因子FF=31.9%。

关键词：二维材料；钙钛矿太阳能电池；薄膜制备；光致发光谱

Abstract

Organic metal halide perovskite solar cells are solar cells with the solid-state perovskite structure as the light-absorbing layer, and they have the advantages of low manufacturing cost and appropriate band gap. However, they also have the disadvantages of poor stability and containing toxic elements, such as Pb. At present, the efficiency of two-dimensional (3D) perovskite solar cells has reached 20%, and the efficiency of more stable two-dimensional (2D) perovskite solar cells has only reached about 10%. In this work, the optimization of the preparation of a stable 2D perovskite film material (BA)₂(MA)_n-1Pb_nI_{3n 1}(n=3) was studied. Three different types of preparation processes were used. For the first type of process, after spin coating, the perovskite spin-on glass was annealed at room temperature, 90℃, 120℃, 150℃ and 180℃ for 15 min, respectively. For the second type of process, before spin coating, the glass was heated at room temperature, 90℃, 120℃, 150℃ and 180℃, respectively, and no annealing was carried out after spin coating. For the third type of process, before spin coating, the glass was heated at room temperature, 90℃, 120℃, 150℃ and 180℃, respectively, and annealing was carried out at 100℃ for 15 min. Based on the observation using optical microscopy, the morphology of the perovskite thin film was the best when the third type of process was used. Fabrication of the solar cell device was completed after the perovskite thin film was prepared.

The perovskite thin films prepared using the third type of process were characterized and tested. Through scanning electron microscopy (SEM), it was observed that the size of the grains in the perovskite thin film was about 34 nm, and the thickness of the thin film was about 2 μm. Through X-ray diffraction (XRD), the strongest XRD diffraction peaks were observed at the crystal planes of (111) and (222). Through photolumilescence (PL) and ultra-violet-visible absorption spectrum (UV – VIS) tests, the optical band gap in the 2D materials was about 2.0 eV, and the band gap slightly changed with the change of temperature. Perovskite solar cells devices were fabricated using the perovskite thin film prepared by spin coating at 90℃ and 180℃ using the third type of process, and the structure of the perovskite solar cells devices was doped fluoride SnO₂ transparent conductive glass (FTO-glass)/ compact TiO₂/ mesoporous TiO₂/ perovskite materials / Spiro-OMeTAD (2,2',7,7'- Tetrakis [N,N-di(4-Methoxyphenyl)aMino] -9,9'-spirobifluorene)/ Au. Their photoelectric conversion performances were tested. The 2D perovskite solar cells annealed at the 180 ℃ had the initial power conversion efficiency of 2.42%, the open circuit voltage V_oc of 0.837 V, short circuit current density J_sc of 9.09 mA/cm², and fill factor FF of 31.9%.

Key Words：Two-dimensional material; perovskite solar cell; preparation of thin film; photolumilescence

目　录

第1章 绪论 1

1.1 前言 1

1.2有机金属卤化物钙钛矿太阳能电池材料简介 2

1.3 有机金属卤化物钙钛矿薄膜材料的研究概况 5

1.4 研究的目的及研究内容 7

第2章 实验部分 8

2.1 材料的制备 8

2.1.1 MAI的制备 10

2.1.2 BAI的制备 11

2.1.3 钙钛矿前躯体溶液的配制 13

2.1.4 钙钛矿薄膜的旋涂 13

2.2 太阳能电池器件的组装 14

2.3 材料的测试 15

2.3.1 扫描电子显微镜及光学显微镜形貌分析 15

2.3.2 X射线衍射分析 16

2.3.3 光致发光光谱 16

2.3.4 紫外可见吸收光谱 16

2.3.5 器件性能测试 17

第3章 结果与讨论 18

3.1 钙钛矿薄膜材料的表征测试 18

3.1.1 钙钛矿薄膜材料的形貌特征 18

3.1.2 钙钛矿薄膜的结构及性能特点 21

3.2 钙钛矿太阳能电池器件的性能测试 24

第4章　总结与展望 26

4.1 总结 26

4.2 展望 26

参考文献 28

致　谢 31

第1章 绪论

1.1 前言

最近几年来，石油，煤炭等化石能源的开采和使用给生活环境照成了巨大的污染，例如全球气候变暖，雾霾问题等等。此外，经济的快速发展，离不开能源的使用，进一步加剧了能源的消耗，21世纪人类将面临巨大的能源短缺问题。由于太阳能这一能源具有环保、干净、可再生等种种优点，如何才能高效利用太阳能，已经成为众多研究者研究的一个热门方向^[1]。

太阳能电池是一种装置，它可以方便，快速的将光能转化为电能。太阳能电池经历了不断发展，到如今大致经过了三个阶段：第一代包括了单晶硅及多晶硅太阳能电池；第二代包括非晶硅薄膜电池及多晶硅薄膜电池；第三代则是一些新概念电池，如量子点电池、染料敏化电池及有机太阳能电池等，图1.1揭示了不同太阳能电池的成本和转换效率之间的关系^[2]。