【Device Papers】Flexible a-Ga₂O₃ solar-blind photodetectors with comprehensive optoelectronic and mechanical properties for imaging sensor arrays and spatial light source detection

      Researchers from the Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences have published a dissertation titled "Flexible a-Ga₂O₃ solar-blind photodetectors with comprehensive optoelectronic and mechanical properties for imaging sensor arrays and spatial light source detection" in Journal of Alloys and Compounds.

Abstract

     Gallium oxide (Ga₂O₃) is emerging as a paramount material for developing high-performance solar-blind photodetectors (SBPDs). Nevertheless, conventional Ga₂O₃ SBPDs, which are typically fabricated on rigid substrates, exhibit limitations in satisfying the burgeoning requirements for wearable, portable, and flexible display applications. Flexible substrates are often constrained by several intrinsic limitations including significant surface roughness, inferior surface quality, a high coefficient of thermal expansion, and limited thermal stability at elevated temperatures. In this work, high-quality amorphous gallium oxide (a-Ga₂O₃) film has been deposited on polyimide substrates using pulsed sputtering deposition (PSD) at a high deposition rate of 76.4 nm/min under room temperature. Through hydrogen rapid thermal annealing (H₂ RTA), the flexible a-Ga₂O₃ SBPDs have demonstrated ultrahigh responsivity of 222.98 A/W, ultrahigh rejection ratio (R₂₄₇/R₄₀₀) of 9.49 × 10⁵ and fast response time of 0.43/0.4 s. By the bending fatigue testing, the flexible photodetector has exhibited excellent mechanical stability and photocurrent stabilization rate of over 90 %. The superior performance of the flexible photodetector is attributed to the combined effects of PSD and H₂ RTA. Finally, flexible imaging sensor arrays and spatial light source detection have been successfully demonstrated which could be an effective approach for largescale fabrication of flexible imaging systems.

DOI：

https://doi.org/10.1016/j.jallcom.2025.179836