ABSTRACT Dark‐current suppression while enhancing photocurrent remains a critical challenge in photodetectors. Optimizing the structure of optoelectronic devices and selecting appropriate optoelectronic materials to achieve overall performance improvement have always been the goals of researchers. We introduce an Al/p‐Si/Al 2 O 3 /ZnO/2‐Au photodetector that builds upon a three‐electrode, coupled architecture by inserting an ultrathin Al 2 O 3 insulator between p‐Si and ZnO. Leveraging the ultrathin dielectric layer, Schottky junctions, and three‐electrode coupling, we reshape the charge distribution so that the dominant electric field orientation switches from vertical (two‐electrode device) to lateral (three‐electrode device). This suppresses the dark current to 2.95 × 10 −9 A at 10 V. At a bias of 5 V, a wavelength of 365 nm and an illumination power density of 0.688 µW/cm 2 , the device delivers a photocurrent responsivity (R) of 662 A/W, a specific detectivity (D*) of 2.15 × 10 1 6 Jones, an external quantum efficiency (EQE) of 2252 %, and switching rise/fall times of 0.10/0.11 s.
Wei et al. (Fri,) studied this question.