Solar-Blind UV Photodetector Based on Atomic Layer-Deposited Cu(2)O and Nanomembrane β-Ga(2)O(3) pn Oxide Heterojunction

[Image: see text] Herein, we present a solar-blind ultraviolet photodetector realized using atomic layer-deposited p-type cuprous oxide (Cu(2)O) underneath a mechanically exfoliated n-type β-gallium oxide (β-Ga(2)O(3)) nanomembrane. The atomic layer deposition process of the Cu(2)O film applies bis(N,N′-di-secbutylacetamidinato)dicopper(I) [Cu((5)Bu-Me-amd)](2) as a novel Cu precursor and water vapor as an oxidant. The exfoliated β-Ga(2)O(3) nanomembrane was transferred to the top of the Cu(2)O layer surface to realize a unique oxide pn heterojunction, which is not easy to realize by conventional oxide epitaxy techniques. The current–voltage (I–V) characteristics of the fabricated pn heterojunction diode show the typical rectifying behavior. The fabricated Cu(2)O/β-Ga(2)O(3) photodetector achieves sensitive detection of current at the picoampere scale in the reverse mode. This work provides a new approach to integrate all oxide heterojunctions using membrane transfer and bonding techniques, which goes beyond the limitation of conventional heteroepitaxy.