Photoconductive organic-inorganic composite materials and their applications in optoelectronic devices

该项目的主要目标是通过开发光导材料作为光电子器件，特别是聚合物太阳能电池的中间层来克服电导率低的问题。本文提出的光导材料是由氧化锌、二氧化钛等无机半导体与有机光敏剂，特别是二酰亚胺等有机光敏剂复合而成的，其增强的电导是基于有机染料向无机半导体的光致电子转移。无机半导体和有机染料分子之间的能级排列对于它们之间的光致电子转移是至关重要的。有机分子和无机半导体之间的相互作用必须抑制一类分子之间的分子间相互作用，以避免可能的相分离，从而获得分子分散的掺杂体系。因此，分子设计的能级排列和适当的相互作用是必不可少的一步。在此方案中，将寻求复合材料掺杂浓度的优化和器件工程。因此，材料合成和器件制造构成了该项目的两个主要目标，将分别在德国和中国的两个研究小组进行探索。

The main objective of this project is to overcome the low conductivity problem by developing photoconductive materials for the application as interlayers in optoelectronic devices, especially in polymer solar cells. Photoconductive materials proposed here are the composite of inorganic semiconductors like zinc oxide and titanium dioxide and organic photosensitizers, in particular perylene bisimide dyes, and the enhanced conductivity is based on the photo-induced electron transfer from organic dyes to the inorganic semiconductor. The energy level alignment between the inorganic semiconductor and organic dye molecule is essential for the photo-induced electron transfer between them. The interaction between the organic molecule and the inorganic semiconductor must suppress intermolecular interactions between molecules of one type to avoid the possible phase separation, and thus obtain a molecularly dispersed doping system. Thus, the molecular design for the energy level alignment and also for the proper interactions is the essential step. The optimization of the doping concentration of the composite materials and the device engineering will be then pursued in this proposal. Accordingly, the materials synthesis and device fabrication comprise the major two objectives of this project that will be explored in two research groups in Germany and China, respectively.