All-metal oxide transparent photodetector for broad responses

All transparent photodetector is realized by metal oxide heterojuction of p-NiO and n-TiO2. This transparent photodetector is self-operation by photovoltaic effect without an external bias. By forming the built-in potential between two metal oxide layers, spontaneously established electric field controls the carrier collections. Silver nanowires (AgNWs) were applied as a top contact and fluorine-doped tin-oxide (FTO) layer worked as a back contact. The relatively high transparency (similar to 44 %) was secured for the photodetector of AgNWs/NiO/TiO2/FTO/Glass. To realize high-performing and broad wavelength photodetection, energy band tuning was performed by N-2-doping process. The N-2-treated transparent photodetector effectively detect UV, blue and green light with a high photocurrent of 558, 171 and 66 mu A, respectively. Moreover, the photodetector achieved excellent responsivity (136 mA/W), detectivity (1.11 x 10(9) Jones), noise-equivalent power (9.2 x 10(-10) W.Hz(-1/2)) and linear-dynamic-range (34 dB). The functional doping of wide-bandgap metal-oxides modifies band energies, which suggests the high possibility of broad photodetection and improved photoelectric devices, including photovoltaics. (C) 2020 Elsevier B.V. All rights reserved.