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

Here, the authors report the realization of light-emitting field-effect transistors based on van der Waals heterostructures with conduction and valence band edges at the Gamma-point of the Brillouin zone, showing electrically tunable and material-dependent electroluminescence spectra at room temperature. 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.

Automated summary

This study demonstrates the realization of light-emitting field-effect transistors based on van der Waals heterostructures. The devices showed electrically tunable and material-dependent electroluminescence spectra at room temperature, making them promising for controlling the spectrum of emitted light. The study also proposes the use of atomically thin semiconductors as a platform for achieving large spectral changes in electroluminescence.