Improving Wearable Photodetector Textiles via Precise Energy Level Alignment and Plasmonic Effect

Light-weight and ultraflexible-fiber-based devices that can be woven into wearable electronic products have attracted extensive attention in recent years. However, fiber-shaped photodetectors (PDs) made from bulky metal-wire-based inorganic semiconductors are prone to damage with excessive bending. Therefore, this work introduces a directly constructed photodetector textile (PDT) and realizes a large-area, organized and dense weaving of fiber-shaped PDs for the first time. To form the structure, ZnO nanorod arrays (NRAs) are grown uniformly on the surface of Ni wire textile to fabricate an Ni-based ZnO NRA textile, then Ag nanowires (NWs) and graphene film (outmost layer) are successively assembled on the functional textile. The precise energy level alignment of the structure is in favor of the separation and transportation of photoinduced carriers, and Ag NWs also bring about near-filed enhancement effect on ZnO NRAs due to local surface plasmon resonances, leading to excellent device performance. The photoresponsivity under bias of 1 V is 0.27 A W-1, and the l(light)/l(dark) ratio calculated form the l-V curves even reaches approximate to 10(2), about two orders of magnitude larger than that of the reported fiber-shaped PDs. Meanwhile, the whole structure also exhibits excellent durability under bending operations, which is ideal for wearable applications.