标题：Unraveling the Mechanism of Photoinduced Charge-Transfer Process in Bilayer Heterojunction
作者：Jin, Hao; Li, Jianwei; Wei, Yadong; Dai, Ying; Guo, Hong
作者机构：[Jin, Hao; Li, Jianwei; Wei, Yadong; Guo, Hong] Shenzhen Univ, Coll Phys & Energy, Shenzhen Key Lab Adv Thin Films & Applicat, Shenzhen 518060, People 更多
通讯作者地址：[Wei, YD]Shenzhen Univ, Coll Phys & Energy, Shenzhen Key Lab Adv Thin Films & Applicat, Shenzhen 518060, Peoples R China.
来源：ACS APPLIED MATERIALS & INTERFACES
关键词：Two-dimensional heterostructure; solar cell; charge-transfer dynamics;; built-in electric field; type-II band alignment; Z-scheme
摘要：Charge transfer is a fundamental process that determines the performance of solar cell devices. Although great efforts have been made, the detailed mechanism of charge-transfer process across the two-dimensional van der Waals (vdW) heterostructure remains elusive. Here, on the basis of the ab initio nonadiabatic molecular dynamics simulation, we model the photoinduced charge-transfer dynamics at the InSe/InTe vdW heterostructures. Our results show that carriers can follow either the R-scheme or Z-scheme transfer path, depending on the coupling between the interlayer states at the band-edge positions. In addition, the charge-transfer dynamics can be effectively controlled by the external parameters, such as strains and interlayer stacking configurations. The predicated electron-hole recombination lifetime in the R-scheme transfer path is up to 1.4 ns, whereas it is shortened to 1.2 ps in the Z-scheme transfer path. The proposed R-scheme and Z-scheme are further verified by the quantum transport simulations on the basis of the density functional theory (DFT) method combined with nonequilibrium Green's functions (NEGF-DFT). The analysis reveals that the system dominated by the Z-scheme shows better performance, which can be attributed to the built-in electric field that facilitates the charge transfer. Our work may pave the way for the designing of next-generation devices for light detecting and harvesting.