Many experiments have indicated that large polaron may be formed in hybrid perovskite, and its existence is proposed to enhance the long lifetime for the carriers. However, detailed theoretical study of the large polaron and its effect on carrier transport at the atomic level is still lacking. Here, we implement tight-binding model fitted from the density-functional theory and we find that the formation energy of the large polaron is around -12 meV. By performing the explicit time-dependent wavefunction evolution of the polaron state, the diffusion constant and mobility of the large polaron state driven by the dynamic disorder and the sublattice vibration are obtained.
创建: Oct 22, 2021 | 20:53
Plasmon photochemistry can potentially play a significant role in photocatalysis. To realize this potential, it is critical to enhance the plasmon excited hot carrier transfer and collection. We apply the non-adiabatic molecular dynamics (NAMD) simulation to study hot carrier dynamics in the system of Au nanocluster on top of GaN surface. By setting up the initial excited hole in Au, the carrier transfer from Au to GaN is found to be on a sub-pico second time scale. By applying different external potentials to mimic the Schottky-barrier band bending, the charge transfer efficiency can be enhanced, demonstrating the importance of the internal electric field. Finally, with the understanding of the carrier transfer’s pathway, we suggest that a ZnO layer between GaN and Au can effectively block the “cold” carrier from returning back to Au but still allow the hot carrier to transfer from Au to GaN.
创建: Oct 22, 2021 | 17:33
