低串联电阻p-型染料敏化太阳能电池结构设计与载流子传输机制

The development of the efficient p-type dye sensitized solar cells (DSC) is the key elements in achieving a high effective pn-type DSC. However, the high series resistance of p-type DSC is the bottleneck, which leads to the poor charge transport performance. This program aims to modify the NiO photo electrode by doping method, and synthesize compact layer in the FTO/NiO photo electrode interface by pulsed laser deposition (PLD) method, which will decrease the series resistance of cells and strengthen the directional transport of charge. The research contents include investigating the effect of doping photo electrode and interface modification on the micro/nano structure, surface state and band structure of NiO photo electrode; elucidating the relation between the type of dopant ions, the property of compact layer and the micro/nano structure of NiO photo electrode with the charge transport and interface transfer procss. Based on the photoelectrochemical property of p-type DSC, the mechanism of the charge transport and photoelectron conversion performance will be revealed. The achievements of the research will be helpful for understanding the p-type DSC, improve the the photoelectron conversion performance of p-type DSC, and accelerate the application of DSC.

p-型染料敏化太阳能电池的研究是发展高效pn-型染料敏化太阳能电池的基础和重点。针对p-型染料敏化太阳能电池串联电阻高，导致载流子传输能力差的关键问题，本项目拟采用价带修饰和受主替位掺杂方式改性NiO光电极，并结合脉冲激光沉积技术（PLD）在NiO光电极/导电基底界面构建致密层，协同降低p-型染料敏化太阳能电池的串联电阻，提高载流子的传输能力，疏通空穴的正向传输通道；明确掺杂改性及界面调控方式对NiO光电极微纳结构、表面态及能带结构的影响规律；阐明掺杂离子类型、致密层及NiO光电极微纳结构与载流子传输及界面转移行为之间的构效关系；结合电池整体性能评价结果，深入理解掺杂改性及界面调控对载流子传输及光电转换性能的作用机制。本项目的研究有助于丰富p-型染料敏化太阳能电池的理论体系，可进一步提升p-型染料敏化太阳能电池性能，推进染料敏化太阳能电池的发展。

针对p-型染料敏化太阳能电池串联电阻高，导致载流子传输能力差的关键问题，设计了Li掺杂NiO光电极有效提高载流子的传输能力，疏通空穴的正向传输通道； 并明确掺杂改性对界面化学电容，捕获态分布及能带结构等方面的影响规律，以及由此带来的界面载流子转移性能和光电转换性能的变化。 研究结果表明Li+掺杂后价带向下偏移和捕获态分布变窄减少了捕获态与染料能级的交叠，抑制了界面复合。Li+掺杂NiO基p型DSSCs抑制了界面复合，改善了空穴的传输，最终提高了电池的光伏性能。p-型半导体/电解质/染料界面复合式造成p-型DSSCs光电性能差的主因。针对界面复合严重问题，详细研究p-型NiO电极表面化学结构、能级结构、捕获态等与光电极/染料/电解质界面载流子传输动力学的构效关系，及其对载流子的传输机制及光电转换性能的影响规律。研究结果表明NiO捕获态分布广导致界面复合严重。降低界面降低电极表面Ni3+（NiOOH）缺陷的浓度，可抑制NiO/电解质界面载流子的复合几率。研究成果发表在Electrochimica Acta， Chemical Engineering Journal，Journal of Photochemistry and Photobiology A-Chemistry ，Applied Catalysis B-Environmental等期刊共9篇；相关研究成果共申请发明专利6项。