【Device Papers】Catalyst-Dependent Solar-Blind Photodetection in β-Ga₂O₃ Nanowire Network MSM Photodetectors

      Researchers from Kakao Company have published a dissertation titled " Catalyst-Dependent Solar-Blind Photodetection in β-Ga₂O₃ Nanowire Network MSM Photodetectors " in IEEE Sensors Journal.

Abstract

      Solar-blind ultraviolet (UV) photodetectors based on β-Ga₂O₃ have attracted significant attention owing to their ultra-wide bandgap and intrinsic visible-blind characteristics. In this work, catalyst-assisted β-Ga₂O₃ nanowire (NW) networks were directly grown on c-plane sapphire substrates by pulsed laser deposition (PLD) using ultrathin metal catalyst layers (Au, Ag, Cu, Ni, and Ti), followed by the fabrication of Ti/Au-contacted metal–semiconductor–metal (MSM) photodetectors. By systematically varying only the catalyst species under otherwise identical growth and device conditions, the effects of catalyst selection on nanowire morphology and photodetector performance were directly compared. The catalyst species strongly influenced both the morphology of the as-grown nanowires and the electrical/photoresponse characteristics of the resulting devices. Under 254 nm illumination, the Ag-assisted device exhibited the highest photocurrent-related performance, including the highest responsivity, external quantum efficiency (EQE), and specific detectivity (D^*). In contrast, the Ni-assisted device showed the lowest dark current and the highest photo-to-dark current ratio (PDCR), indicating a clear catalyst-dependent trade-off between high-responsivity operation and low-leakage, high-contrast photodetection. The observed catalyst-dependent trends are likely associated with the coupled effects of nanowire morphology, network connectivity, and defect-related carrier transport, rather than a single growth-related factor alone. These results suggest that catalyst engineering is an effective process-level strategy for tailoring β-Ga₂O₃ nanowire network MSM photodetectors for either high-responsivity or low-leakage, high-contrast UV photodetection.

DOI：

https://doi.org/10.1109/JSEN.2026.3733395