A Langmuir-Like Adsorption Model for MoS2 Gas Sensors: Bridging Theory and Experiment
Gas sensors based on layered TMDCs (transition-metal dichalcogenides) such as MoS2 have attracted considerable attention recently and are considered as a promising alternative to the conventional metal-oxide-based gas sensing devices. Recent studies on TMDC gas sensors have mainly addressed either the theoretical description of adsorption mechanisms or the fabrication of test devices and the investigation of their gas sensing performance. However, a suitable approach for modeling the gas sensing behavior of TMDC devices and for establishing a reliable connection between theoretical results and the response of experimental devices when exposed to gases remains absent. To bridge this gap, in the present work a new Langmuir-based adsorption model, capable of calculating both the sensor sensitivity and selectivity, is developed and applied to MoS2-based gas sensors. It is shown that by using appropriate published data for the adsorption energy and the charge transfer as input data, the reported experimental sensitivities of MoS2 gas sensors can be well reproduced by the model.