Effect of Deposition Temperature on the Characteristics of Ga2O3 Films Grown on Flexible Mica and the Performance of Corresponding Photodetectors

Abstract

In this study, we fabricated flexible Ga₂O₃ photodetectors (PDs) based on Ga₂O₃/mica flexible structures obtained at different substrate temperatures. Higher substrate temperatures result in higher quality crystals for the film, but they also reduce the photoresponsivity of the PD. Meanwhile, the dark current of the PD gradually decreases, and the response time is significantly shortened. The PD fabricated at 440 °C exhibited a responsivity of 4.45 W/A at 20 V bias and weak UV illumination of approximately 380 μW/cm² (at 254 nm). It also demonstrated a high detectivity (D*) of 6.07 × 10¹² Jones and an extremely low noise equivalent power (NEP) of 4.42 × 10^–13 W/Hz^1/2. At 680 °C, the PD exhibits an extremely low dark current (1.6 × 10^–13 A at 20 V) and a fast response time (τ_rise: 0.89 s, τ_decay: 0.26 s). Additionally, in bending tests, the PDs maintained nearly constant performance, demonstrating excellent flexibility and revealing the potential applications of Ga₂O₃ flexible PDs in future wearable electronics.