Constructing van der Waals (vdW) semiconductor heterostructures is a possible approach to optimize the optoelectronic properties, and understanding photogenerated charge carrier dynamics at vdW heterostructure interfaces is of crucial importance. By using time-dependent ab initio nonadiabatic molecular dynamics simulations, we study the dynamics of photogenerated electrons at a BP/InSe heterostructure interface and observethe highly efficient separation of photogenerated electron-hole pairs at the interface. Instead of direct tunneling, the ultrafast transfer of excited electrons is significantly promoted by an adiabatic mechanism related to thermally excited nuclear motions stemming from strong e-p coupling and phonon excitation, and a small energy difference of donor-acceptor states. The internal quantum efficiency for charge separation can reach up to 99.6% and improved optical absorption is also observed in this heterostructure, making the BP/InSe heterostructure a compelling optoelectronic material.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Materials Chemistry C|
|State||Published - Jan 15 2019|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-09
Acknowledgements: The authors acknowledge financial support from the National Natural Science Foundation of China (NSFC No. 517222008), the Key Technologies Research and Development Program of Sichuan Province (No. 2018JY0007), and the Graduate Student's Research and Innovation Fund of Sichuan University (No. 2018YJSY009). The authors thank Prof. Jürgen Rödel (Technische Universität Darmstadt) for providing the ferroelectric analyzer (aixACCT TF Analyzer 2000), Mrs Hui Wang (Analytical & Testing Center of Sichuan University) for collecting FE-SEM images, and Dr Junwei Zhang and Prof. Xi-xiang Zhang (King Abdullah University of Science and Technology) for collecting TEM images.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.