Adsorption and sensing performances of vacancy defects and Cu-embedded GaN/MoTe2 heterostructure for harmful gases: A DFT study

Abstract

By utilizing density functional theory (DFT), we explore the adsorption and sensing performance of NO, NO2, SO2 and CO on intrinsic GaN/MoTe2 heterostructure, vacancy-defective GaN/MoTe2 heterostructures and Cu-embedded GaN/MoTe2 heterostructures, respectively. The results indicate that the VGa-GaN/MoTe2 heterostructure exhibits higher adsorption energy (yielding more negative values) for all four gases, demonstrating superior adsorption performance compared to the intrinsic system. Similarly, the Cu-GaN/MoTe2 heterostructure also improves the adsorption performance for nitrogen oxides. Meanwhile, the Cu-MoTe2/GaN heterostructure also significantly outperforms the intrinsic systems in terms of adsorption performance for the four harmful gases. Particularly, the Cu-MoTe2/GaN heterostructure has an adsorption energy of −2.22 eV for NO2 and a charge transfer amount of up to 0.72 e, indicating a strong chemical interaction between the adsorption system and gas molecules. Therefore, Cu-MoTe2/GaN is a potential ideal gas adsorption material. This work offers a theoretical foundation for transition metal-doped semiconductor heterostructures for future research.