Strong mid-infrared photoresponse in small-twist-angle bilayer graphene
arXiv:2012.12443 · doi:10.1038/s41566-020-0644-7
Abstract
Recently the small-twist-angle (< 2°) bilayer graphene has received extraordinary attentions due to its exciting physical properties. Compared with monolayer graphene, the Brillouin zone folding in twisted bilayer graphene (TBG) leads to the formation of superlattice bandgap and significant modification of density of states. However, these emerging properties have rarely been leveraged for the realization of new optoelectronic devices. Here we demonstrate the strong, gate-tunable photoresponse in mid-infrared wavelength range of 5 to 12 um. A maximum extrinsic photoresponsivity of 26 mA/W has been achieved at 12 um when the Fermi level in a 1.81° TBG is tuned to its superlattice bandgap. Moreover, the strong photoresponse critically depends on the formation of superlattice bandgap, and it vanishes in the gapless case with ultrasmall twist angle (< 0.5°). Our demonstration reveals the promising optical properties of TBG and provides an alternative material platform for tunable mid-infrared optoelectronics.
25 pages, 3 figures. Published version
References in corpus (8)
- Universal Dynamic Conductivity and Quantized Visible Opacity of Suspended Graphene
- Mechanisms of photoconductivity in atomically thin MoS2
- Lattice relaxation and energy band modulation in twisted bilayer graphenes
- Superlattice-induced insulating states and valley-protected orbits in twisted bilayer graphene
- Numerical studies of confined states in rotated bilayers of graphene
- Interlayer coupling in commensurate and incommensurate bilayer structures of transition metal dichalcogenides
- Optical Conductivity of Twisted Bilayer Graphene
- Gate tunable optical absorption and band structure of twisted bilayer graphene
Cited by in corpus (15)
- Fabrication methods for integrating 2D materials
- Light-matter coupling and quantum geometry in moiré materials
- Nano-imaging photoresponse in a moiré unit cell
- Giant ultra-broadband photoconductivity in twisted graphene heterostructures
- Engineering transistor-like optical gain in two-dimensional materials with Berry curvature dipoles
- Wafer-scale Programmed Assembly of One-atom-thick Crystals
- Optical response of two-dimensional Dirac materials with a flat band
- Emerging chiral optics from chiral interfaces
- Effects of heterostrain and lattice relaxation on optical conductivity of twisted bilayer graphene
- Photonics in Flatland: Challenges and Opportunities for Nanophotonics with 2D Semiconductors
- Infrared photoresistance as a sensitive probe of electronic transport in twisted bilayer graphene
- Optical properties of two dimensional Dirac Weyl materials with a flatband
- Direct Photocurrent Detection of Optical Vortex Based on the Orbital Photo Galvanic Effect: Progress, Challenge and Perspective
- Correlated Insulator Moiré Bolometer
- Local optical conductivity of strain solitons in bilayer graphene with arbitrary soliton angle