Photographic Materials And Derivatives Molecular Charge Transfer Mechanism

At present, the energy issue has become the focus of the whole world, Energy is the important material base of national economy, and it is the basic condition of human survival.The development and utilization of new energy every time, all will inevitably lead to the change of world energy structure, promoting the economy development. But on the current situation of our country, the development of China’s energy industry relatively lags behind the pace of overall development of the national economy, China’s energy is facing serious challenges. At present, China’s main energy: coal, oil, natural gas and other non renewable resources. With the development of economy of these energy nearly depleted, and these fuels will release a lot of harmful gas combustion, not only pollute the air, but also do harm to human health,therefore, human hope urgently to find new clean energy. Abundant, clean and pollution-free solar energy will undoubtedly become the focus of mankind, converting solar energy into chemical energy and electric energy and so on. At present, people focus on the development and utilization of solar energy battery. Dye sensitized solar cell combined with dye sensitizer and inorganic semiconductor advantage, with its simple production process, relatively high photoelectric conversion efficiency, and has a broad spectrum of influence range, low cost, less pollution and other advantages of rapid become the majority of scientists and research hot spot and focus of scientific workers.Dye sensitizer molecules is an important part of the dye-sensitized solar cells, therefore conducts the theory research to it, has the important meaning to improve the photoelectric conversion efficiency of the dye-sensitized solar cell.Based on the three kinds of non metal organic dyes SBDPIR690-C60、SBDPIR731-C60 、SBDPIR731-C60 as the research object.In this paper that the ground-state geometry of three kinds of molecular is optimized by use density functional theory(DFT) with the B3 LYP function and 6-311G(d) basis set. The excited state properties of these three molecules were obtained by using TD-DFT/B3LYP/6-311G(d) basis set, at the same time the highest occupied molecular orbital(HOMO) and the lowest for the unoccupied orbital(LUMO) and the energy difference between the two orbital were listed.For HOMO→LUMO Orbital transition, The energy difference of three types molecules: 1.73 e V, 1.64 e V and1.40 e V respectively. For the molecules of SBDPIR690-C60: the molecular absorption spectrum showed two peaks, the peak of 650.18 nm and 423.61 nm, the main to contribution from the the excited state S11 by HOMO-1→LUMO Orbital transition and excited state S42 by HOMO-12→LUMO Orbital transition respectively; For the molecules of SBDPIR731-C60: the molecular absorption spectrum showed two peaks, the peak of 682.69 nm and 461.83 nm, the main to contribution from the the excited state S9 by HOMO-1→LUMO+1 Orbital transition and excited state S36 by HOMO-10→LUMO+1 Orbital transition respectively; For the molecules of SBDPIR840-C60: the molecular absorption spectrum showed two peaks, the peak of 815.16 nm and 576.95 nm, the main to contribution from the the excited state S4 by HOMO→LUMO+1 Orbital transition and excited state S17 by HOMO-3→LUMO+1 Orbital transition respectively. In order to further study the intramolecular lectron transfer, we use the three-dimensional real space analysis method(transition density(TD), charge difference densities(CDD)) for their visualization, transition density(TD) reveals the strength and direction of the transition dipole moment; charge difference densities(CDD) reveals the intramolecular charge transfer direction. The use of the two-dimensional(2D) real space analysis method to analyze coherence of the electron hole. Finally, the results of the calculation are compared with experimental values, consistent. We can provide a theoretical reference for future research dye sensitizer by studying the three molecular of poperties.