External Electric Field-Dependent Photoinduced Charge Transfer At Donor-PC₇₁BM System For An Organic Solar Cell

In recent years, more and more people familiar with solar energy resources, facing of coal, oil and other energy is not renewable and reserves decreasing sharply problems, solar energy as the new way obtain all the extensive attention.As early as the end of the last century, organic solar cells has developed,organic semiconductor materials for photoelectric conversion of the active material,with its simple production process, a wide range of sources of raw materials with its huge reserves, low prices, thin thickness, do a large area flexible device has the advantages and obtain the scientists favor, with broad prospects for development and application prospect, is already in the field of new materials and new energy field is full of vigor and vitality of one of the frontiers. However, the low photoelectric conversion efficiency of organic solar cells is an important problem to restrict the promotion of organic solar cells.This paper selects cyanide methylene amide fullerene (Cyanomethylene-CPDT-BTI-PC71BM) and combined Ker-imide fullerene Dithienosilole-BTI-PC71BM as the research object, the main use of quantum chemical study on the theory and methods of two kinds of molecular systems in the light induced charge transfer. First, using TD-DFT theory B3LYP functional and 6-31G basis set was used to optimize the molecular geometry, and on this basis on the properties,do the ground state properties of theoretical calculation; then change the molecular reaction environment, in reaction to join the direction and size of different applied electric field, and time-dependent density functional theory TD-DFT-B3LYP-6-31G (d) method of molecular excitation state characteristics are calculated, the transition energies, absorption wavelength and the corresponding oscillator strength and from Homo to LUMO transition configuration mutual action factor of excited state information. Based on using the visualization of three-dimensional (3D) light induced charge transfer process visualization, clear charge transfer direction,Base on Marcus theory, to study the Charge reorganization energy and charge transfer energy during molecular charge transfer, to explore the applied electric field effects of the photoelectric conversion efficiency,and enable us to a deeper understanding of organic polymer solar battery photoelectric conversion mechanism, to prepare for design to high conversion efficiency of organic solar cells in the furter, improve the photoelectric conversion efficiency of the organic polymer solar cells provided the theory foundation.