Bright visible light emission from graphene

TL;DR

This paper reports the first observation of bright visible-light emission from electrically biased suspended graphene, achieved by localizing hot electrons and tuning emission via optical interference, enabling scalable, flexible light emitters.

Contribution

It demonstrates bright visible-light emission from suspended graphene with enhanced thermal radiation efficiency and tunable spectrum, advancing graphene-based optoelectronic applications.

Findings

Bright visible-light emission observed from suspended graphene.

Enhanced thermal radiation efficiency by 1000-fold.

Scalable arrays of graphene light emitters created.

Abstract

Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible, and transparent optoelectronics. In particular, the strong light-matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators, and plasmonic devices. In addition, electrically biased graphene on SiO2 substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here we report the observation of bright visible-light emission from electrically biased suspended graphenes. In these devices, heat transport is greatly minimised; thus hot electrons (~ 2800 K) become spatially localised at the centre of graphene layer, resulting in a 1000-fold enhancement in the thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be utilized to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene bright visible-light emitters. These results pave the way towards the realisation of commercially viable large-scale, atomically-thin, flexible and transparent light emitters and displays with low-operation voltage, and graphene-based, on-chip ultrafast optical communications.