Enhancing surface activity in MoTe2 monolayers through p-block doping: A comprehensive DFT investigation

Abstract

Molybdenum ditelluride (MoTe2), a member of the transition metal dichalcogenides (TMDs), has recently garnered significant attention in the fast growing fields of two-dimensional electronics. However, despite its advantages, the intrinsic properties of MoTe2, like the low chemical activity of its basal plane, also resulted in several technological challenges. To overcome these limitations, several methods have been explored, with single atom doping emerging as a particularly promising approach. In this study, we employed density functional theory (DFT) to investigate the influence of single atom impurities on the chemical activity of MoTe2. A total of 22 dopants were selected from the p-block of the periodic table, ranging from boron to bismuth. Specifically, we examined the adsorption of oxygen molecules (O2) on the doped structures to assess their impact on layer chemical activity. Our findings revealed that doping was energetically favorable for all investigated atoms, and it had a significant effect on surface activity. Notably, doping with dopants from groups 13–15, especially those with low atomic number, results in significant increased adsorption strength, leading to weakening of the molecular bonding in O2 by up 5.72 eV, hinting at the potential use as catalyst. Additionally, we identified certain molecules, primarily from group 17, with a remarkably high adsorption energy to charge transfer ratio. This leads to excellent sensing characteristics, where the response to adsorption in their carrier concentration is increased 100-fold over the pristine MoTe2, while sensor recovery is estimated between 0.01 and 2 s.