Ion-gel-based light-emitting devices using transition metal dichalcogenides and hexagonal boron nitride heterostructures

Fabrication of high-performance optoelectronic devices is an important aspect of the application research of transition metal dichalcogenides (TMDCs). In this study, heterostructures of TMDCs and hexagonal boron nitrides (hBN) were successfully fabricated into light-emitting devices. Monolayer and artificially stacked homobilayer WS 2 were prepared on hBN, respectively. They were then deposited with electrodes and covered by the ion gels to function as light-emitting devices. Both devices showed clear electroluminescence (EL) with voltages of ∼3 V. In monolayer device, a symmetric EL peak was observed with suppressed inhomogeneity. The bilayer device showed spectra that agreed with the natural bilayer samples. These results indicate the enhancement of the optical performance of TMDCs and the heterostructure could expand the potential of TMDC-based light-emitting devices.