title: Nanocavity Integrated van der Waals Heterostructure Light-Emitting Tunneling Diode.
abstract: Developing a nanoscale, integrable, and electrically pumped single mode light source is an essential step toward on-chip optical information technologies and sensors. Here, we demonstrate nanocavity enhanced electroluminescence in van der Waals heterostructures (vdWhs) at room temperature. The vertically assembled light-emitting device uses graphene/boron nitride as top and bottom tunneling contacts and monolayer WSe2as an active light emitter. By integrating a photonic crystal cavity on top of the vdWh, we observe the electroluminescence is locally enhanced (>4 times) by the nanocavity. The emission at the cavity resonance is single mode and highly linearly polarized (84%) along the cavity mode. By applying voltage pulses, we demonstrate direct modulation of this single mode electroluminescence at a speed of ∼1 MHz, which is faster than most of the planar optoelectronics based on transition metal chalcogenides (TMDCs). Our work shows that cavity integrated vdWhs present a promising nanoscale optoelectronic platform.
authors.forename: Chang-Hua
authors.identifier: 0000-0001-8042-9218
authors.initials: CH
authors.lastname: Liu
authors.forename: Genevieve
authors.initials: G
authors.lastname: Clark
authors.forename: Taylor
authors.initials: T
authors.lastname: Fryett
authors.forename: Sanfeng
authors.identifier: 0000-0002-6227-6286
authors.initials: S
authors.lastname: Wu
authors.forename: Jiajiu
authors.identifier: 0000-0003-1527-201X
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Physics, Humboldt University , D-12489 Berlin, Germany.
authors.forename: Fariba
authors.initials: F
authors.lastname: Hatami
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xu
authors.forename: Arka
authors.initials: A
authors.lastname: Majumdar
keywords: Electroluminescence; optoelectronics; photonic crystal cavity; transition metal dichalcogenides; van der Waals heterostructure