Novel Red Emission from MoO3/MoS2-MoO2-MoO3 Core-Shell Belt Surface.

Electrically driven red emission from MoS2-MoO2-MoO3 (MS-MO) hybrid-based metal-semiconductor-metal (MSM) devices is reported for the first time. MoO3 belts with high crystal quality and sufficient size are synthesized by thermal deposition. A layer of MS-MO hybrid is then produced on the belt surface to form MoO3/MS-MO core-shell by sulfurization. The devices exhibit unique electrical properties, a nonlinear I- V curve, and electric hysteresis characteristics at high applied biases (>2.4 V), where MS-MO hybrids act as electron transport channels. The electroluminescent current of the device increases to a set current limit over time when a constant bias is applied. The novel characteristics of the device are attributed to the space charge limited conduction (SCLC) mechanism occurring in MS-MO hybrids. The strong light emission is from recombination of excitons within the MoS2 phase. This work develops a simple and effective method to drive MoS2 to emit light on a large scale without using monolayer MoS2 and vertical p-n junctions, indicating great potential for future 2D optoelectronics and photonics applications.