Influences of Work Function Changes in NO2 and H2S Adsorption on Pd-Doped ZnGa2O4(111) Thin Films: First-Principles Studies

Abstract

The work function variations of NO2 and H2S molecules on Pd-adsorbed ZnGa2O4(111) were calculated using first-principle calculations. For the bonding of a nitrogen atom from a single NO2 molecule to a Pd atom, the maximum work function change was +1.37 eV, and for the bonding of two NO2 molecules to a Pd atom, the maximum work function change was +2.37 eV. For H2S adsorption, the maximum work function change was reduced from −0.90 eV to −1.82 eV for bonding sulfur atoms from a single and two H2S molecules to a Pd atom, respectively. Thus, for both NO2 and H2S, the work function change increased with an increase in gas concentration, showing that Pd-decorated ZnGa2O4(111) is a suitable material in NO2/H2S gas detectors.

Growth and Characterization of Sputtered InAlN Nanorods on Sapphire Substrates for Acetone Gas Sensing

“…Furthermore, the energies of the vacuum level and Fermi level, work function, and work function change in our geometric models are shown in Table 1 . In our previous studies [ 37 , 38 , 39 ], the alterations in the work function of CO, NO 2 , and H 2 S molecules upon interaction with the ZnGa 2 O 4 (111) surface align with experimental findings. These changes in the work function signify the overcoming of electron barriers induced by gas adsorption, contributing to the quantitative assessment of gas-sensing characteristics in zinc gallium oxide.…”

“…Since InAlN is an n -type semiconductor and acetone gas is a reducing gas, a reduction in depletion width layers is favorable upon exposure to reducing gas. In recent studies, we have successfully illustrated the electron flow from the reducing gas to the n -type semiconductor until the Fermi level equilibrium is achieved [ 37 , 38 , 39 ]. This phenomenon leads to the formation of ohmic contact.…”

Molybdenum Carbide MXenes as Efficient Nanosensors toward Selected Chemical Warfare Agents

“…Thus, during gas adsorption reactions, the change in ϕ can identify the sensitivity response of the sensor to detect the particular gas. − The work function can be calculated as follows: ϕ = V ( ∞ ) − ε normalf where V (∞) and ε f represent the electrostatic potential at the point far from the target surface (vacuum) and Fermi level of the system, respectively.…”