Indoor Light-Activated Cone-Shaped MoS2 bilayers-based NO Gas Sensor with PPb-Level Detection at Room-temperature

Yu-Ze Chen^1*, Sheng-Wen Wang², Hao-Chung Kuo², Yu-Lun Chueh¹

¹Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
²Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan

* Presenter:Yu-Ze Chen, email:kinorassic@gmail.com

Utilization of light to boost the performance of gas sensors allows us to operate sensor devices at room temperature. Here, we, for the first time, demonstrated an indoor light-activated 3D cone-shaped MoS2 bilayers-based NO Gas sensor with ppb-level detection operated at room-temperature. A large-area cone-shaped (CS)-MoS2 bilayers were grown by depositing 2 nm-thick MoO3 layers on a 2" three-dimensional (3D) cone-patterned sapphire substrate (CPSS) followed by a sulfurization process via chemical vapor deposition. Because the exposed area of MoS2 bilayers is increased by 30 %, the CS-MoS2 gas sensor (GS) demonstrated excellent performance with a response of ~470 % and a fast response time of ~25 s after exposure to 1 ppm of NO gas illuminated by an ultraviolet (UV) light with a wavelength of 365 nm. Such extraordinary performance at room temperature is attributed to the enhanced light absorption because of the light scattering effect caused by the 3D configuration and photo-desorption induced by UV illumination.

Keywords: Chemical vapor deposition, molybdenum disulfide, patterned sapphire substrate, gas sensor, white light