Molding 2D Exciton Flux toward Room Temperature Excitonic Devices

Devices operating with excitons have promising prospects for overcoming the dilemma of response time and integration in current generation of electron- or/and photon-based elements and devices. In combination with the advantages of emerging twistronics and valleytronics, the atomically thin transition metal dichalcogenide semiconductors open up new opportunities for pursuing practical excitonic devices, where the strong exciton binding energy enables operating exciton at room temperature. The essential and foremost step toward exciton devices is the control of spatiotemporal exciton flux, which is density-dependent and affected by the complex many-body interactions. It can be effectively controlled by the strain, electric field, electron-doping, and local dielectric environment. Intriguingly, exotic phenomena such as exciton condensation, electron-hole liquid, exciton Hall effects, and exciton halo effects can be occurred in 2D exciton system, providing new possibilities for excitonic devices. Up to now, the proof-of-principle of room temperature exciton devices, including excitonic switching and transistor, exciton guides, and excitonic nanolaser, have been realized. Here the authors review the recent advances in molding 2D exciton flux from basic principle, manipulation, exotic phenomena to promising applications and discuss the opportunities and challenges in pushing the frontiers of room temperature excitonic devices.

Automated summary

Devices operating with excitons offer potential solutions to the response time and integration challenges faced by current electron-based or/and photon-based devices. Atomically thin transition metal dichalcogenide semiconductors, combined with twistronics and valleytronics, present new opportunities for practical excitonic devices. The control of spatiotemporal exciton flux is a crucial step, which can be achieved through various methods such as strain, electric field, electron-doping, and local dielectric environment. Exciting phenomena like exciton condensation and exciton Hall effects can occur in 2D exciton systems, providing new possibilities for excitonic devices. Proof-of-principle exciton devices at room temperature, including excitonic switching and transistor, exciton guides, and excitonic nanolaser, have been achieved. This review discusses the recent advances in shaping 2D exciton flux, as well as the opportunities and challenges in advancing room temperature excitonic devices.