联系我们
意见反馈

关注公众号

获得最新科研资讯

Computational Material Science Group

简介

分享到
实验室简介

We develop and use ab initio methods to simulate carrier dynamics in materials. By developing and applying the first-priniciple’s computation methods, I am interested in illustrating the ultrafast process of the excited carriers’ motion in various materials/devices, including bulk materials, interfaces, chemical reactions, and nano-materials. Understanding these processes will help to design more efficient materials or devices.

还没有发布内容

Large Polaron Formation and its Effect on Electron Transport in Halide Perovskite

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.

Hot-carrier cooling and charge transfer across interface

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.

访问量:112