Two-Dimensional Gallium Oxide Monolayer for Gas-Sensing Application

Abstract

A two-dimensional (2D) Ga 2 O 3 monolayer with an asymmetric quintuple-layer configuration was reported as a novel 2D material with excellent stability and strain tunability. This unusual asymmetrical structure opens up new possibilities for improving the selectivity and sensitivity of gas sensors by using selected surface orientations. In this study, the surface adsorptions of nine molecular gases, namely, O 2 , CO 2 , CO, SO 2 , NO 2 , H 2 S, NO, NH 3 , and H 2 O, on the 2D Ga 2 O 3 monolayer are systematically investigated through first-principles calculations. The intrinsic dipole of the system leads to different adsorption energies and changes in the electronic structures between the top-and bottom-surface adsorptions. Analyses of electronic structures and charge transport calculations indicate a potential application of the 2D Ga 2 O 3 monolayer as a room-temperature NO gas-sensing device with high sensitivity and tunable adsorption energy using plenary strain-induced lattice distortion.

Phase transition of two-dimensional ferroelectric and paraelectric Ga2O3 monolayers: A density functional theory and machine learning study

“…Recently, two van der Waals 2D ferroelectric (FE) configurations of Ga 2 O 3 were discovered in our previous studies [24,25] by adopting a class of stable single-layer configurations based on III 2 -VI 3 compounds [26][27][28][29] with an asymmetric quintuple-atomic-layer configuration. One Ga 2 O 3 layer consists of five triangular atomic lattices stacked in the sequence O-Ga-O-Ga-O and belongs to the R3m space group (No.…”

Two-dimensional Ferroelectric Ga2O3 Bilayers with Unusual Strain-engineered Interlayer Interactions

“…Our previous studies [37][38][39] revealed a metastable configuration of 2D vdW Ga 2 O 3 monolayer with intrinsic dipole pointing from top to bottom surfaces (i.e., from negatively to positively charged centers). The structure is analogous to ferroelectric zinc blende (FE-ZB ) phase of III 2 −VI 3 compounds [32,40], as shown in Supporting Information Figure S1.…”

Highly sensitive and low-power consumption metalloporphyrin-based junctions for COx detection with excellent recovery

“…8 CO x (the sum of CO and CO 2 ) electrical sensors operate through the changes in the current or voltage in materials. Such changes in material conductivity occur by charge transfer (CT) between the sensor material and the target gases 9,10 via gassensor chemical interaction. To date, many CO x gas sensors have been designed for gas sensing technologies, yet they are restricted by high operating temperature, insufficient sensitivity, and expensiveness.…”