Enhanced performance of self-powered ultraviolet photodetectors coupled with the photovoltaic-pyroelectric effect based on ZnO/CuBO2 core-shell nanorod arrays

An innovative self-powered ultraviolet photodetector based on ZnO/CuBO2 core-shell nanorod arrays was fabricated using cost-efficient and scalable preparation technologies, including a chemical hydrothermal method and an impregnation technique. The ZnO/CuBO2 core-shell heterostructure exhibits significant diode behavior with a rectification ratio approaching 7016 at± 1 V because of the type-II band alignment formed at the heterojunction interface, acquiring a maximum responsivity of 165 mA /W1 with an external quantum efficiency of 55.3% (370 nm, 65 mW cm−2) and specific detectivity (4.13 ×1012 cm Hz1/2 W−1) under zero bias. Simultaneously, by applying an external bias to adjust the photovoltaic and pyroelectric effects and delving into the operating mechanisms, the photodetector based on the ZnO/CuBO2 heterostructure achieves enhanced performance. The decay time has been shortened, and the responsivity has reached up to 38.82 A W−1 (apparent quantum efficiency ~ 13,010%) at − 2.5 V. Moreover, the effects of the power density on the photocurrent response and temperature induced by the photovoltaic-pyroelectric effect are discussed. This study reveals the potential of CuBO2 (one of the Cu-delafossite families) as a hole transport layer in optoelectronic devices, broadens the application prospects of core-shell nanorod arrays based on the photovoltaic-pyroelectric effect, and provides a direction for modulating the performance of such devices.