摘 要

量子点敏化太阳能电池(QDSC)因其较低的成本和高的理论转化效率已成为近年来太阳能电池领域研究的热点。量子点敏化太阳能电池光阳极材料的性能对太阳能电池的性能影响较大。

ZnO光阳极材料与典型的TiO₂光阳极材料相比，有较高的电子迁移率和较高的导带底电位，有利于光生电子的输送，可减少光生电子的复合。此外，ZnO的表面形态在生长过程中更易于调控，特定结构的ZnO可增加太阳光的散射，增大光生电子的捕获率。因此，ZnO将有望取代TiO₂成为QDSC领域中最具有代表性的光阳极材料。

CuInS₂半导体量子点与目前研究比较多的Ⅱ-Ⅵ族（CdX，X=S、Se、Te）和Ⅳ-Ⅵ族（PbS、PdSe）量子点相比，不含镉和铅等重金属元素，具有毒性小、带隙窄、光吸收系数大等特点，在量子点敏化太阳能电池（QDSC）领域极具应用潜力。

基于以上分析，本论文研究了CuInS2量子点敏化ZnO纳米棒光阳极材料。首先通过水热法在FTO导电玻璃上制备了ZnO纳米棒阵列；随后采用连续离子层吸附反应法在ZnO纳米棒上沉积CuInS₂量子点，制备出CuInS₂量子点敏化ZnO光阳极。研究了CuInS₂量子点的不同沉积次数对ZnO纳米棒薄膜紫外可见吸收光谱的影响。通过XRD、EDS、SEM和PL对所制备的样品的晶体结构、化学组分、微观形貌和结构缺陷进行了表征。主要研究结果如下：

（1）通过浸渍提拉法制备了ZnO晶种层，然后利用水热法制备了ZnO纳米棒阵列薄膜。使用XRD、SEM、PL、UV-vis等技术手段对样品进行了表征。结果表明，所合成的ZnO纳米棒沿c轴择优取向生长，为六方纤锌矿结构，长径比为14，对紫外-可见光的吸收较低。

（2）在制备了ZnO纳米棒阵列结构的基础上，采用连续离子层吸附反应法，制备出了CuInS₂量子点敏化ZnO纳米棒光阳极材料。利用XRD、SEM、EDS、UV-vis等技术手段对沉积CuInS₂量子点的ZnO纳米棒薄膜的样品进行了表征。XRD测试结果表明所制备的CuInS₂量子点为黄铜矿结构；SEM分析表明CuInS₂量子点已成功沉积到ZnO纳米棒薄膜上，随着沉积层数的增加，CuInS₂颗粒之间的团聚程度逐渐增加；通过UV-Vis图谱计算出沉积了CuInS2量子点的ZnO纳米棒薄膜的光学带隙从3.22 eV变化为2.98 eV。

关键词：量子点敏化太阳能电池；ZnO纳米棒；CuInS₂量子点；水热法；连续离子层吸附法

Abstract

Quantum dot sensitized solar cells (QDSC) have become a hot research topic in the field of solar cells in recent years due to their low cost and high theoretical conversion efficiency. The choice of photoanode materials has a great influence on the performance of solar cells.

Compared with the typical photoanode material TiO₂, ZnO has higher electron mobility and higher conduction band bottom potential, which is beneficial to the transport of photogenerated electrons and reduces the recombination of photogenerated electrons. In addition, the surface morphology of ZnO is more easily regulated during the growth process. The specific structure of ZnO can increase the scattering of sunlight and increase the capture rate of photogenerated electrons. Therefore, ZnO is expected to replace TiO₂ as the most representative photoanode material in the QDSC field.

CuInS₂ semiconductor quantum dots do not contain heavy metal elements, compared with the II-VI (CdX, X=S, Se, Te) and IV-VI (PbS, PdSe) quantum dots. It has great potential in the field of quantum dot sensitized solar cells (QDSC) due to its low toxicity, narrow band gap, large light absorption coefficient.

Based on the above aspects, our paper systematically studied the photoanode material ZnO nanomaterials and quantum dots CuInS₂ of quantum dot sensitized solar cells. Firstly, ZnO nanorod arrays were prepared on FTO conductive glass by hydrothermal method. Subsequently, CuInS₂ quantum dots were deposited on ZnO nanorod by successive ionic layer adsorption and reaction. The phase composition, crystal structure, microstructure and structural defects of the obtained samples were characterized by XRD, EDS, SEM and PL. The effects of different coating times of CuInS₂ quantum dots on the UV-visible absorption spectra of ZnO nanorod films were investigated by UV-vis test. The main findings are as follows:

1、The ZnO seed layer was prepared by the dip-coating method, and then the ZnO nanorod arrays were prepared by hydrothermal method. The samples were characterized by XRD, SEM, PL, and UV-vis techniques. The results show that the synthesized ZnO nanorods grow in a preferred orientation along the c-axis, which is a hexagonal wurtzite structure with an aspect ratio of 14 and low absorption of UV-visible light.

2、CuInS₂ quantum dots with different layers were deposited on the ZnO nanorod films by successive ionic layer adsorption and reaction. The samples were characterized by XRD, SEM, EDS and UV-vis techniques. The XRD results show that the prepared CuInS₂ quantum dots are chalcopyrite structure; SEM results show that CuInS₂ quantum dots have been successfully deposited on ZnO nanorod films. As the number of coating layer increases, the degree of agglomeration between CuInS₂ particles increases gradually; The optical band gap of the ZnO nanorod films deposited with CuInS₂ quantum dots was changed from 3.22 eV to 2.98 eV by UV-Vis pattern.

Key Words: quantum dot sensitized solar cells; ZnO nanorods; CuInS₂ quantum dots; hydrothermal method; successive ionic layer adsorption and reaction

目录

摘 要 Ⅰ

Abstract Ⅱ

第1章绪论 1

1.1引言 1

1.2 太阳能电池简介 1

1.2.1硅基太阳能电池 2

1.2.2化合物半导体太阳能电池 2

1.2.3染料敏化太阳能电池 3

1.2.4量子点敏化太阳能电池 3

1.3 ZnO纳米材料 5

1.3.1 ZnO纳米材料简介 5

1.3.2 ZnO纳米材料制备方法 6

1.3.2.1气相沉积法 6

1.3.2.2 液相反应法 6

1.3.2.3 固相反应法 7

1.4 CuInS₂量子点 7

1.4.1 CuInS₂ 量子点简介 7

1.4.2 CuInS₂ 量子点制备方法 8

1.4.2.1 热注入法 8

1.4.2.2 溶剂热法 8

1.4.2.3 胶体化学法 8

1.4.2.4 连续离子层吸附反应法 9

1.5课题研究的内容和思路 9

第2章 ZnO纳米棒的水热法制备和性能研究 11

2.1 实验部分 11

2.1.1 实验原料和主要设备 11

2.1.2 实验过程 12

2.1.2.1 FTO玻璃基板的切割及清洗 12

2.1.2.2 ZnO晶种层的制备 12

2.1.2.3 水热法生长制备ZnO纳米棒阵列薄膜 12

2.1.3 ZnO纳米棒的测试表征方法 13

2.2 实验结果与讨论 14

2.2.1 X射线衍射（XRD）分析 14

2.2.2 扫描电子显微镜（SEM）分析 14

2.2.3 光致发光光谱（PL）分析 15

2.2.4 紫外可见吸收光谱（UV-Vis）分析 16

2.3 本章小结 16

第3章 CuInS₂ /ZnO复合光阳极的制备与性能研究 18

3.1连续离子层吸附反应法制备CuInS₂ /ZnO复合光阳极 18

3.1.1 实验部分 18

3.1.1.1 实验原料和设备 18

3.1.1.2 实验过程 19

3.1.1.3 CuInS₂量子点敏化ZnO光阳极的测试表征方法 19

3.1.2 实验结果与讨论 20

3.1.2.1 X射线衍射（XRD）分析 20