CO sensing properties of nanostructured WSe2/GaN and MoSe2/GaN based gas sensors

Abstract

The sensing properties of GaN and hydrothermal synthesized transition metal di-selenides nanostructure decorated WSe 2 /GaN and MoSe 2 /GaN hybrid structures are reported for 100 ppm CO gas for temperature range of 27 °C–250 °C. The fabricated devices divulged that Schottky Barrier Height increases from 0.6 eV to 1.2 eV with increment in temperature while vice versa was perceived for series resistance, except for MoSe 2 /GaN structure. The gas sensing measurements revealed that the threshold temperature for CO sensing for GaN, WSe 2 /GaN and MoSe 2 /GaN based sensors was 100 °C, 100 °C and 150 °C along with a peak response value of 23.3 %, 38.8 % and 43.1 %, respectively. The gas sensing data displayed a highly competitive response & recovery time as all the fabricated devices were able to detect CO within 78 s of exposure. The recovery time of the devices varied in a similar fashion, demonstrating the promising potential of W(Mo)Se 2 /GaN hybrid structures for efficient CO gas detection. • GaN & TMDC hybrid structure based sensor for CO gas sensing. • Hydrothermally synthesized WSe 2 and MoSe 2 nanostructured on GaN for CO gas sensing. • Threshold temperature for CO sensing for GaN & its heterostructure varies between 100 o C- 150 °C. • MoSe 2 /GaN & WSe 2 /GaN devices with highly competitive response & recovery time is fabricated.