Electrical Control of Electroluminescence in 2D Semiconductor Light Emitting Device through Synchronous Injection of Electrons and Holes

Abstract

Achieving efficient electroluminescence (EL) in 2D materials requires precise control over the injection and recombination of charge carriers-electrons and holes. In this study, a method is introduced to improve charge carrier injection in using transition metal dichalcogenides (TMDCs) based light emitting devices driven by alternating current (AC), achieved through dual pulse injection. The dual pulse device exhibits a notable enhancement in EL intensity, displaying a substantial increase as compared to the single pulse device, achieving an approximate sixfold improvement. The proposed dual pulse operated device configuration enables the independent control of electron and hole injection, facilitating the fine-tuning of carrier recombination processes to improve the EL emission efficiency. Phase delay dependent EL characteristics are observed featuring a maximum integrated EL at a phase delay of 180 degrees indicating an enhanced EL emission during out-of-phase pulse operation between the electrodes. Moreover, the dual pulse device exhibited a approximate to 3.5-fold improvement in the device EL external efficiency (eta e) when compared to the device operated with a single pulse. Manipulating carrier recombination in TMDCs-based LEDs opens up new opportunities to enhance their performance, enabling practical applications in display technology, lighting, optical communication, and electrically tunable light sources.