Solar-Blind Ultraviolet Photodetectors Based on Porous β-Ga2O3 Nanorods for Deep-Ultraviolet Communications

Ultraviolet communication is a promising candidate for applications in short-range military communications, internal safety communication in aerospace, etc. Nevertheless, traditional detectors for deep ultraviolet light frequently necessitate high driving voltages and rely heavily on filters. Nanomaterials are efficient means to develop high-performance photodetectors based on their high surface-to-volume ratio, quantum effect, and high light field confinement ability. Herein, the one-dimensional (1D) porous Ga₂O₃ nanorods are fabricated through a straightforward hydrothermal method. Subsequent to optimizing the crystallinity characteristics of these nanorods, the solar blind ultraviolet photodetector (SBPD) performances are studied in detail, including rising edge, falling edge, responsiveness, and switching ratio. Notably, the device with the highest oxygen defect concentration shows a high photo-to-dark current ratio of 10⁶, a fast response time of 28 ms, a responsivity of ∼0.9 mA/W, and a detectivity of 1.4 × 10⁹ Jones, respectively. Furthermore, by using this detector as the signal receiver and a commercial light-emitting diode (LED) with a peak wavelength of 254 nm as the emitter, a deep ultraviolet optical wireless communication (OWC) system is established, employing on–off-keying (OOK) modulation to transmit ASCII codes at a data rate of 50 bps. The received signal increased with the application of bias voltage, successfully transmitting the message “SEU-2024-2025”. This work highlights the potential of 1D porous ultrawide bandgap semiconductor nanorods in deep-ultraviolet photodetection and optical communications.