有机功能分子界面修饰对有机/无机复合太阳电池性能的调控

The properties of the organic polymer/inorganic semiconductor hybrid photoactive layer play a vital role in the photovoltaic performance in organic/inorganic hybrid solar cells, as the active layer creates charges and presents percolation pathways in dividual components to transport holes and electrons, determining the interfacial charge seperation, transfer, and recombination. For poly (3-hexylthiophene) (P3HT)/TiO2 hybrid solar cell, the photo-to-electric conversion efficiency is very low due to its poor interfacial charge separation and transfer efficiencies. In this proposal, a series of oligo(thiophene)s derivatives with appropriate electron energy levels, molecular polarity, and hydrophobic properties etc., will be designed and synthesized. The motivation of this study is to control the performance of P3HT/TiO2 hybrid solar cells through interfacial modification by using organic functional molecules based on oligo(thiophene)s derivatives. Interfacial modification using oligo(thiophene)s derivatives can improve both the morphology of P3HT/TiO2 heterojunction film and the electrical properties of the heterojunction interfaces, which will increase the efficiencies of the interfacial charge separation and transfer, and substantially improve device performance..The correlation between the structures of oligo(thiophene)s derivatives and P3HT/TiO2 heterojunction morphology, electrical properties of heterojunction interface, as well as the performance of the cells will be systematically investigated by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, transient photovoltage, and electrochemical impedance spectra measurements, etc.. The mechanism of controlling the performance of P3HT/TiO2 hybrid solar cells via interfacial modification with organic functional molecules based on oligo(thiophene)s derivatives will be explored, hence increase the efficiency of organic conjugated polymer/inorganic semiconductor nanocrystals hybrid solar cells via interfacial modification with functional oligomer molecules.

在有机聚合物/无机半导体复合太阳电池中，光活性层有机共轭聚合物/无机半导体复合膜的界面性质决定器件的界面电荷分离，扩散与复合动力学过程，对电池的光电转换性能起至关重要的作用。传统的聚（3－己基噻吩）（P3HT）/TiO2复合太阳电池界面电荷分离与传输效率较低，导致其光电转换性能较差。针对这一问题，我们拟设计合成具有合适电子能级，分子极性，和亲疏水性等性质的齐聚噻吩衍生物类有机功能分子，利用齐聚噻吩衍生物对P3HT/TiO2异质结界面进行修饰，通过协同改善复合膜的微观形貌和异质结界面的电学性质，提高电池的界面电荷分离与传输效率，最终提高其光电转换性能。结合X射线衍射、原子力显微镜、X射线光电子能谱、瞬态光电压、电化学阻抗等测试，系统研究基于齐聚噻吩的有机功能分子界面修饰对P3HT/TiO2复合电池光电转换性能的调控机理，进而提高有机共轭聚合物/无机半导体纳米晶复合太阳电池的光电转换效率。

随着社会经济的发展，能源危机与环境污染日益加剧。太阳能取之不尽，用之不竭，是无污染可再生的绿色新能源。大规模的光伏发电不仅绿色环保，还可以改变我国的传统能源结构，具有重大的社会和经济价值。有机/无机复合太阳电池以制备工艺简单、理论光电转换效率高和价格低廉等优点引起了学术界和产业界的广泛重视。有机/无机复合太阳电池主要由导电基底，纳米多孔半导体薄膜，染料，氧化还原电解质或有机空穴传输材料、以及对电极组成。在有机/无机复合太阳电池中，界面性质决定器件的界面电荷分离，扩散与复合动力学过程，对电池的光电转换性能起至关重要的作用。本人主要通过改善复合光伏太阳电池中异质结界面的电学性质，提高电池界面电荷分离和传输效率，最终提高电池的光电转换性能。分别在TiO2纳米管阵列的合成，电泳沉积TiO2致密层，在有机共轭聚合物合成中预引入氧化还原电解质，自组装硫化物电极的合成，界面性质对电池性能的调控机理以及它们在有机/无机复合太阳电池中的应用等方面开展了详细研究，并取得了重要研究进展。为进一步研发不同结构的有机/无机复合太阳电池，更深入地理解光伏电池的工作原理，提高相应光伏器件的光电转换效率提供了理论与实验依据。