Room‐Temperature Exciton‐Based Optoelectronic Switch

Abstract Excitons, bound pairs of electrons and holes, could act as an intermediary between electronic signal processing and optical transmission, thus speeding up the interconnection of photoelectric communication. However, up to date, exciton‐based logic devices such as switches that work at room temperature are still lacking. This work presents a prototype of a room‐temperature optoelectronic switch based on excitons in WSe₂ monolayer. The emission intensity of WSe₂ stacked on Au and SiO₂ substrates exhibits completely opposite behaviors upon applying gate voltages. Such observation can be ascribed to different doping behaviors of WSe₂ caused by charge‐transfer and chemical‐doping effect at WSe₂/Au and WSe₂/SiO₂ interfaces, respectively, together with the charge‐drift effect. These interesting features can be utilized for optoelectronic switching, confirmed by the cyclic PL switching test for a long time exceeding 4000 s. This study offers a universal and reliable approach for the fabrication of exciton‐based optoelectronic switches, which would be essential in integrated nanophotonics.