染料敏化太阳能电池光电极界面栅栏构筑及界面电荷转移机制

The charge recombination reaction on the "TiO2/dye/electrolyte" interface of dye sensitized solar cells (DSCs) is the main reason which results in the photoelectric conversion efficiency lowing so much than the theoretical value. One strategy is to develop new interface structure to control the interface properties precisely. The aim of this program is to design and construct "fence-like" insulating layers on the interface, which will not reduce the dye loading, and not block the injecting process of the photogenerated electron from the excited dye to the conduction band of TiO2. The "fence-like" insulating layer can inhibit the charge recombination reaction on the interface and show the plasmon-enhanced effect. The research contents include the construction of "fence-like" insulating layer, the investigation of the interactions between insulating layer and TiO2, dye, electrolyte respectively, and the analysis of the effects of the interactions on the optical and electrochemical properties of DSCs. Based on the analysis results, the working mechanism of "fence-like" insulating layer on the performance of DSCs will be discussed. The charge recombination process on the interface can be inhibited by controlling the insulating layer precisely. The achievements of the research will be helpful for understanding the electron transfer process better and developing new structures and methods to inhibit the charge recombination on the interface. Furthermore, the research results will promote the improvement on the photoelectron conversion performance of DSCs, and accelerate the development of DSCs.

"TiO2/染料/电解质"界面电荷复合是造成染料敏化太阳能电池实际效率远低于理论值的一个重要原因。对界面结构和特性进行精细调控是抑制界面电荷复合的关键。本项目拟从界面结构设计出发，构造基于"栅栏"结构的界面隔离层，既不减少染料吸附量、不阻隔光生电子从染料向TiO2导带的注入，同时有效抑制界面电荷复合反应，兼具表面等离子体增强效应；明确界面"栅栏"与TiO2、染料、电解质之间的相互作用，及其对光的吸收性能、电荷传输与界面转移等微观行为的影响规律；阐明界面"栅栏"结构和组成对载流子在界面的行为及电池光电转换性能的作用机制；实现对载流子界面行为的调控。本项目的研究成果有助于从微观层面进一步认识界面载流子行为，并为开发抑制界面复合反应的新方法、新结构提供更加丰富的理论基础，有助于进一步提高染料敏化太阳能电池效率,促进染料敏化太阳能电池的发展。

染料敏化太阳能电池是一种基于有机染料-无机纳米半导体晶体相结合的光电转换器件，具有吸收光谱范围宽、易加工、可柔性化、可连续化涂布生产等优势。染料敏化太阳能电池的理论转换效率超过30%，然后目前的最高记录还未超过15%。“TiO2/染料/电解质”界面电荷复合是造成染料敏化太阳能电池实际效率远低于理论值的一个重要原因，因此对界面结构和特性进行精细调控是抑制界面电荷复合的关键。本项目从界面结构设计出发，构造TiO2-R 结构、TiO2-AuxAg1-x-HS-R 结构、TiO2-AuxAg1-x-HS-R-SiO2 等不同“栅栏”结构的界面隔离层，同时研究了高透明导电的导电玻璃、高催化活性的对电极，以及采用透明导电纳米晶增加光电极收集效率，在既不减少染料吸附量、不阻隔光生电子从染料向 TiO2 导带的注入的同时，有效抑制界面电荷复合反应，兼具表面等离子体增强效应。经过界面“栅栏”修饰，光电转换效率提高超过10%。通过研究，明确了界面“栅栏”其对光的吸收性能、电荷传输与界面转移等微观行为的影响规律，阐明了界面“栅栏”结构和组成对载流子在界面的行为及电池光电转换性能的作用机制，实现对载流子界面行为的调控。本项目的研究成果有助于从微观层面进一步认识界面载流子行为，并开发抑制界面复合反应的新方法、新结构。