Superflexible, Self-Biased, High-Voltage-Stable, and Seal-Packed Office-Paper Based Gallium-Oxide Photodetector

This research presents a solar-blind (UVC) office paper-based photodetector that is self-biased, superflexible, nonwettable, high-performance, and high-voltage stable. In contrast to the traditional design of photodetectors involving sophisticated techniques, this study reports unique and facile hand-sketched bottom asymmetric graphite and silver electrodes. The asymmetric bottom electrodes offer minimum reflectivity that limits the dark current to 1.2 pA and boosts the device performance even at zero bias; this results in a significantly increased On/Off ratio of more than 104 at 254 nm. The photodetector exhibits high responsivity (3.1 mA W–1), and fast response (0.459 s/0.386 s), even at zero bias. For good formability deformations (30 cm–1) as well as for wide turning angles (±180°), a high strenuous durability test demonstrated impressive photoswitching characteristics. Highly stable bottom electrodes contributed to the exceptionally stable operation (>720 h) and much enhanced performance along with tremendous capability of bearing high voltages up to 100 V. The performance of the reported photodetector has considerably exceeded previously published photodetectors even on costly nonflexible substrates. Moreover, the paper-based device was coated with UV transparent enamel paint to make it completely protected from wettability.