Enhanced Sensitivity of MoTe2 Chemical Sensor through Light Illumination

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) semiconducting materials have recently attracted wide attention and been regarded as promising building blocks for chemical sensors due to their high surface-to-volume ratio. However, their low response hinders the realization of high-performance 2D TMDCs chemical sensors. Here, we demonstrate the improvement of sensing performance of molybdenum ditelluride (MoTe2) gas sensor through continuous light illumination. The dependence of sensing performance on the energy of photons and light intensity is systematically studied. The response to NH3 is dramatically enhanced by more than 25 times under 254 nm ultraviolet (UV) light illumination with intensity of 2.5 mW/cm2. Moreover, a remarkable low detection limit of 3 ppb is achieved, which is improved by 80 times compared with that in dark condition. The results demonstrate that light illumination is a promising method to improve the sensitivity of 2D TMDCs chemical sensors.