Improved Sensitivity in Schottky Contacted Two-Dimensional MoS₂ Gas Sensor

Abstract

Two-dimensional (2D) transition-metal dichalcogenides have attracted significant attention as gas-sensing materials owing to their superior responsivity at room temperature and their possible application as flexible electronic devices. Especially, reliable responsivity and selectivity for various environmentally harmful gases are the main requirements for the future chemiresistive-type gas sensor applications. In this study, we demonstrate improved sensitivity of a 2D MoS 2 -based gas sensor by controlling the Schottky barrier height. Chemical vapor deposition process was performed at low temperature to obtain layer-controlled 2D MoS 2 , and the NO 2 gas responsivity was confirmed by the fabricated gas sensor. Then, the number of MoS 2 layers was fixed and the types of electrode materials were varied for controlling the Schottky barrier height. As the Schottky barrier height increased, the NO 2 responsivity increased, and it was found to be effective for CO and CO 2 gases, which had little reactivity in 2D MoS 2 -based gas sensors.

Recent advances in 2D/nanostructured metal sulfide-based gas sensors: mechanisms, applications, and perspectives

“…110 The Schottky barrier height (SBH) from the metal side remains unchanged, while the bias . 111 The SB is determined from the difference between 4 m and 4 s , strongly inuenced by the gas molecules. Therefore, the SBH is easily varied owing to the change of the gas concentration.…”

Atomic‐Layer‐Deposition‐Based 2D Transition Metal Chalcogenides: Synthesis, Modulation, and Applications

“…The application of 2D TMCs to gas sensing devices has been widely studied owing to their sensitive response to various gas molecules and low operation temperature, which leads to a low power consumption. [14,16,[181][182][183] A 2D WSe 2 gas sensor exhibited an outstanding NO 2 sensing performance (4140%) at room temperature and NO 2 selectivity. [77] The temperature dependence of the recovery of WSe 2 gas sensors and the effect of selective catalytic reduction reaction on the associated recovery property were studied.…”

Advanced Strategies to Improve Performances of Molybdenum-Based Gas Sensors

“…The different channel length is also crucial for the device with a shorter channel length shows a relatively higher response than a long channel, as the charges undergo less scattering during transport through a shorter channel. Another report from Kim et al [ 243 ] has investigated the difference in channel materials. Three different metals were used.…”