Photogalvanic Effect in The Be₂Ga Monolayer-Based Photodetector Device

In this study, we have constructed a two-probe photodetector device with the armchair and zigzag configurations using the planar hexacoordinate two-dimensional (2D) Be 2 Ga monolayer. The linear and elliptical photogalvanic effect (PGE) has been considered, which is a physical phenomenon that generates photocurrents under zero bias conditions without the necessity of constructing a [Formula: see text]–[Formula: see text] junction, and is essential for understanding the photovoltaic properties of the photodetector device. The results revealed that the photocurrents produced in the Be 2 Ga photodetectors are mostly cosine and sine with respect to twice the polarization angle or the elliptic angle of incident light, and photon energy and polarization angle can alter these relations. Interestingly, when vacancy- and substitution-doping were introduced with the symmetry of the Be 2 Ga monolayer reduced from D 6H to D 3H , the PGEs can produce very high photocurrents, showing a large enhancement of PGEs. Except for the zigzag vacancy-Be 1 case, with its largest photocurrent increasing to 51.7[Formula: see text][Formula: see text]/photon (about 10 4 times the original one), the photocurrents for the other doping cases increase by a factor of about 10–100, showing that the asymmetry is crucial to generate prodigious PGEs. In addition, the armchair and zigzag Be 2 Ga photodetectors have significantly higher extinction ratios, showing they are indicative of the sensitivity of Be 2 Ga photodetectors to polarized light and suggesting that they have a clear advantage in resolving polarized light. Consequently, given the potential applications of Be 2 Ga monolayer in photodetector devices, it can be concluded that this 2D material is a highly promising candidate for the construction of photodetector devices.