Negative Photoconductivity in 2D α-MoO 3 /Ir Self-Powered Photodetector: Impact of Post-Annealing.

Surface plasmon technology is regarded as having significant potential for the enhancement of the performance of 2D oxide semiconductors, especially in terms of improving the light absorption of 2D MoO 3 photodetectors. An ultrathin MoO 3 /Ir/SiO 2 /Si heterojunction Schottky self-powered photodetector is introduced here to showcase positive photoconductivity. In wafer-scale production, the initial un-annealed Mo/2 nm Ir/SiO 2 /Si sample displays a sheet carrier concentration of 5.76 × 10 11 /cm², which subsequently increases to 6.74 × 10 12 /cm² after annealing treatment, showing a negative photoconductivity behavior at a 0 V bias voltage. This suggests that annealing enhances the diffusion of Ir into the MoO 3 layer, resulting in an increased phonon scattering probability and, consequently, an extension of the negative photoconductivity behavior. This underscores the significance of negative photoconductive devices in the realm of optoelectronic applications.