Self-powered solar-blind UV/visible dual-band photodetection based on a solid-state PEDOT:PSS/α-Ga2O3 nanorod array/FTO photodetector

Abstract

Through the construction of a PEDOT:PSS/α-Ga₂O₃ heterojuntion on FTO by hydrothermal, low-temperature annealing and spin-coating processes, a self-powered PEDOT:PSS/α-Ga₂O₃ nanorod array/FTO photodetector has successfully realized dual-band photodetection; it possesses a solar-blind UV main band with a peak responsivity of ∼1.43 mA W⁻¹ at 245 nm and a visible subband with a peak responsivity of ∼0.07 mA W⁻¹ at 540 nm. Due to the highly efficient PEDOT:PSS/α-Ga₂O₃ heterojuntion, the peak responsivity in the solar-blind UV range is not only ∼10⁴ times as high as that of the compared α-Ga₂O₃/FTO photodetector, but also one of the best values among the popular self-powered α-Ga₂O₃ nanorod array photodetectors based on the liquid-state photoelectrochemical structure, thus indicating the realization of a high-responsivity solid-state device with more convenient operation. More importantly, our photodetector has realized solar-blind UV/visible dual-band photodetection for the first time among self-powered Ga₂O₃-based dual-band photodetectors, which paves a feasible way to demonstrate high-performance solid-state α-Ga₂O₃ solar-blind UV/visible dual-band photodetection by easy, common and low-cost processes.