Self-Powered Photodetector with High Photocurrent and Polarization Sensitivity Based on the GaN/CdO Heterostructure

Two-dimensional (2D) van der Waals (vdW) heterostructures offer new possibilities for enhancing the photocurrent (Iph) of self-powered photodetectors through the photogalvanic effect (PGE). In our research, the electronic, electrical, and photocatalytic properties of the GaN/CdO heterostructure are analyzed using first principles, and the I–V curve and Iph are calculated based on quantum transport simulations. The direct bandgap of the S-type GaN/CdO heterostructure is 1.96 eV, with the built-in electric field. The high solar to hydrogen efficiency (ηSTH) of 32.28% indicates excellent photocatalytic properties, and the low overpotential of 0.52 V suggests excellent electrocatalytic characteristics. The photodetectors based on the GaN/CdO heterostructure exhibit high Iph with a large extinction ratio (ER), which is due to its high anisotropic carrier mobility. The photocurrent increases with bending the photodetector with a high ηSTH at the central angle (φ) of 15°. Our research demonstrates the potential application of the GaN/CdO heterostructure in the photocatalytic and electrocatalytic fields and in photodetectors.