Thermal effects in the ultrafast photoinduced electron transfer from a molecular donor anchored to a semiconductor acceptor

摘要: A nonadiabatic molecular dynamics (MD) simulation of the photoin- duced electron transfer (ET) from a donor to TiO 2 semicon- ductor acceptor is carried out in microcanonical ensemble with an average tem- perature 350 K. The electronic structure dye-semiconductor system and adiabatic are simulated by ab initio MD, while (NA) effects incorporated quantum-classical mean-field approach. ET dy- namics driven thermal fluctuations that dominate ionic motions at simu- lated temperature. ground excited state ion similar; therefore, change quantum force due photoexcitation can be neglected, final analysis greatly simplified. occurs on 5-fs timescale, agreement recent ultrafast experimental data. Vibrational chromophore ring carbons induce oscillation photoexcited energy, resulting bimodal distribution initial conditions for ET. At low energies localized primarily chromophore, high substantially delocalized into first 3 surface layers surface. Thermally domi- nant mechanism. Compared earlier 50 K, rate NA K remains almost unchanged, whereas increases substantially.