Tunable geometric photocurrent in van der Waals heterostructure
- Resource Type
- Authors
- Weibo Gao; Abdullah Rasmita; Chongyun Jiang; Ritesh Agarwal; Zhurun Ji; Hui Ma
- Source
- Subject
- Photocurrent
Materials science
business.industry
Photocurrents
Physics::Optics
Heterojunction
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
Atomic and Molecular Physics, and Optics
Van der Waals Forces
Electronic, Optical and Magnetic Materials
symbols.namesake
Liquid crystal
Quantum Hall Effect
Electric field
Monolayer
symbols
Optoelectronics
van der Waals force
Physics::Optics and light [Science]
business
Circular polarization
Mesoscopic Systems
Spin-½
- Language
- English
Utilizing the spin or valley degree of freedom is a promising approach for realizing more energy-efficient information processing devices. Circularly polarized light can be used to generate spin/valley current in monolayer 2D transition metal dichalcogenides. We observe a geometrically dependent photocurrent in heterostructure M o S 2 / W S e 2 , where light with a different circular polarization generates photocurrents in opposite directions. Furthermore, we show that this photocurrent persists even at room temperature, and it can be controlled using an in-plane electric field and back gating. We explain the observed phenomena via valley-dependent valence band shift and the valley optical selection rule. This finding may facilitate the use of 2D heterostructures as a platform for opto-valleytronics and opto-spintronics devices.