Nat. Commun.: Room-temperature high-speed electrical modulation of excitonic distribution in a monolayer semiconductor

Title：

Room-temperature high-speed electrical modulation of excitonic distribution in a monolayer semiconductor

Authors：

Guangpeng Zhu¹, Lan Zhang¹, Wenfei Li¹, Xiuqi Shi¹, Zhen Zou¹, Qianqian Guo¹, Xiang Li¹, Weigao Xu², Jiansheng Jie¹, Tao Wang¹*, Wei Du¹*, Qihua Xiong^3,4,5,6

Institutions：

¹Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123, P. R. China

²Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, P. R. China

³State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, P. R. China

⁴Frontier Science Center for Quantum Information, Beijing 100084, P. R. China

⁵Beijing Academy of Quantum Information Sciences, Beijing 100193, P. R. China

⁶Collaborative Innovation Center of Quantum Matter, Beijing, P. R. China

Abstract：

Excitons in monolayer semiconductors, benefitting from their large binding energies, hold great potential towards excitonic circuits bridging nano-electronics and photonics. However, achieving room-temperature ultrafast on-chip electrical modulation of excitonic distribution and flow in monolayer semiconductors is nontrivial. Here, utilizing lateral bias, we report high-speed electrical modulation of the excitonic distribution in a monolayer semiconductor junction at room temperature. The alternating charge trapping/detrapping at the two monolayer/electrode interfaces induces a non-uniform carrier distribution, leading to controlled in-plane spatial variations of excitonic populations, and mimicking a bias-driven excitonic flow. This modulation increases with the bias amplitude and eventually saturates, relating to the energetic distribution of trap density of states. The switching time of the modulation is down to 5ns, enabling high-speed excitonic devices. Our findings reveal the trap-assisted exciton engineering in monolayer semiconductors and offer great opportunities for future two-dimensional excitonic devices and circuits.

IF：

17.694

Link：

https://www.nature.com/articles/s41467-023-42568-w