Zr-doping-assisted wet etching for non-destructive transfer of β-Ga2O3 films to fabricate high-performance wearable ultraviolet photodetectors

Abstract

High-quality flexible Ga₂O₃-based solar-blind photodetectors, which are highly regarded for exceptional sensitivity, detectivity, and response speed, can be efficiently fabricated using the wet etching method. However, advancements in this field are hindered by challenges such as the intricate process control and the potential introduction of contaminants and defects, thereby limiting their broader application. In this study, a freestanding, non-destructive β-Ga₂O₃ film is prepared via a Zr-doping-assisted wet etching strategy, and this film is then utilized to fabricate flexible ultraviolet photodetectors. Zr-doping effectively addresses the key challenge of chemical erosion during film transfer, as the stable Zr⁴⁺ reduces oxygen vacancies in β-Ga₂O₃, thus avoiding Cl⁻ corrosion. Benefiting from its low defect concentration, the flexible β-Ga₂O₃:Zr photodetector achieves an impressive photo-to-dark current ratio of 1.2 × 10⁵, a responsivity of 8.6 A W⁻¹, a detectivity of 3.5 × 10¹³ jones, and an external quantum efficiency of 4.20 × 10³%. Additionally, it exhibits remarkable mechanical durability, with stable performance under extreme bending and after 1000 bending cycles. Following 80 hours of salt spray testing, the photodetection performance remains above 91%, confirming the excellent stability in harsh environments. This study establishes a scalable approach for integrating high-quality β-Ga₂O₃ films into flexible electronics, supplying a new pathway for designing high-performance flexible semiconducting devices.