Cross‐Bar SnO2‐NiO Nanofiber‐Array‐Based Transparent Photodetectors with High Detectivity

An cross‐bar structure is employed to design a transparent p‐n junction‐based photodetector. The device consisting of aligned n‐SnO2 and p‐NiO nanofibers is prepared via a mature electrospinning process that is suitable for commercial applications. It exhibits a high detectivity of 2.33 × 1013 Jones under 250 nm illumination at −5 V, outperforming most state‐of‐art SnO2‐based UV photodetectors. It is also endowed with a self‐powered feature due to a photovoltaic effect from the p‐n junction, resulting in a photocurrent of 10−10 A, responsivity of 30.29 mA W−1 at 0 V bias, and detectivity of 2.24 × 1011 Jones at 0.05 V bias. Moreover, the device is highly transparent (over 90% toward visible light) due to the wide band gap of photoactive materials and well‐designed cross‐bar fiber structure. Additionally, an n‐SnO2‐p‐ZnO:Ag (Ag doped ZnO) self‐powered UV photodetector is fabricated that shows good performance and give another example of the use of the cross‐bar structure. A transparent, self‐powered ultra‐violet photodetector with a high detectivity of 1013 Jones is fabricated. It is based on cross‐bar n‐SnO2‐p‐NiO nanofiber arrays synthesized by a simple electrospinning method. The fabric‐like device also exhibits an outstanding responsivity. Furthermore, another high‐performance photodetector based on cross bar SnO2 and Ag‐doped ZnO nanofiber arrays is fabricated.