Light sources with bias tunable spectrum based on van der Waals interface transistors

Abstract

Light-emitting electronic devices are ubiquitous in key areas of current technology, such as data communications, solid-state lighting, displays, and optical interconnects. Controlling the spectrum of the emitted light electrically, by simply acting on the device bias conditions, is an important goal with potential technological repercussions. However, identifying a material platform enabling broad electrical tuning of the spectrum of electroluminescent devices remains challenging. Here, we propose light-emitting field-effect transistors based on van der Waals interfaces of atomically thin semiconductors as a promising class of devices to achieve this goal. We demonstrate that large spectral changes in room-temperature electroluminescence can be controlled both at the device assembly stage –by suitably selecting the material forming the interfaces– and on-chip, by changing the bias to modify the device operation point. Even though the precise relation between device bias and kinetics of the radiative transitions remains to be understood, our experiments show that the physical mechanism responsible for light emission is robust, making these devices compatible with simple large areas device production methods.

Light-emitting devices based on atomically thin MoSe2

“…Beyond individual atomically thin MoSe 2 , MoSe 2 can be stacked with different vdW materials to construct novel heterostructures by vdW interactions, including h-BN/MoSe 2 /h-BN [7] , h-BN/ MoSe 2 /WS 2 /h-BN [8] , and MoSe 2 /WSe 2 [9] . In addition, MoSe 2 or other TMDs can be stacked with many other 2D materials, such as InSe [10,11] , 2D perovskites [12−14] , etc. to form vdW heterostructures with fascinating properties, such as bias tunable spectrum, robust interlayer coupling, valley pseudospin, and interlayer excitons.…”

Electroluminescence from Megasonically Solution-Processed MoS2 Nanosheet Films

“…In particular, transition metal dichalcogenides (TMDs) have been of interest due to their layer-dependent bandstructure, direct bandgap at the monolayer limit, strong light–matter interactions, tightly bound excitons, trions, and multiexcitons that can be controlled by strain , and doping, − solution-processability for printed optoelectronics, − high carrier mobility, , and mechanical flexibility . Furthermore, the ability to stack van der Waals materials without the need for lattice matching has enabled a variety of light-emitting device architectures including lateral p–n homojunctions with a split-gate geometry, , vertical p–n heterojunctions, , and quantum well structures. , Light emission through bipolar carrier injection in metal–semiconductor–insulator–metal (MSIM) capacitor structures has also been pursued for 2D material light-emitting devices for multiple reasons. First, the light-emitting capacitor structure is simpler to fabricate than p–n heterojunctions or quantum well structures .…”