Theoretical Study of Small Molecules Adsorption on Pristine and Transition Metal Doped GeSe Monolayer for Gas Sensing Application

By using first-principles calculations, the sensing properties of pristine and transition metal (TM) atoms (Ti, V, and Co) embedded germanium selenide (GeSe) monolayer toward small gas molecules (H-2, NH3, CO, O-2, SO2, NO, and NO2) were investigated. The adsorption energies, electronic structure, optical properties, and recovery time of the adsorption systems were calculated and analyzed in detail. The results indicate that TM doped GeSe has stronger interaction with gas molecules compared with the pristine GeSe monolayer. Especially for Ti- and V-GeSe monolayer, the absolute value of adsorption energies are up to 2 eV for O-2, NO, and NO2. The doping with TM atoms also changes the charge transfer and electronic structures of adsorption systems. Combined with the result of the calculated optical properties and recovery time, it can be concluded that Ti-GeSe monolayer has great potential for NH3 detection, while Co-GeSe monolayer can be very promising SO2 gas sensors.

Automated summary

The study using first-principle calculations revealed that transition metal-doped germanium selenide monolayers have stronger adsorption capabilities for gas molecules, with Ti and V atoms showing adsorption energies up to 2 eV for O-2, NO, and NO2. The doping of TM atoms alters the charge transfer and electronic structures of the adsorption systems, making Ti-GeSe monolayer suitable for NH3 detection and Co-GeSe monolayer promising for SO2 gas sensors.