A high-performing all-transparent photodetector was created by configuring a MoOx/NiO/ZnO/ITO structure on a glass substrate. The ITO bottom layer was applied as a back contact. To achieve the transparent p/n junction, p-type NiO was coated on the n-type ZnO layer. Reactive sputtering was used to spontaneously form the ZnO or NiO layer. In order to improve the transparent photodetector performance, the functional MoOx window layer was used. Optically, the MoOx window provided a refractive index layer (n=1.39) lower than that of NiO (n=2), increasing the absorption of the incident light wavelengths (λs). Moreover, the MoOx window can provide a lower sheet resistance to improve the carrier collection for the photoresponses. The MoOx/NiO/ZnO/ITO device showed significantly better photoresponses of 877.05 (at λ=460 nm), 87.30 (λ=520 nm), and 30.38 (λ=620 nm), compared to 197.28 (λ=460 nm), 51.74 (λ=520 nm) and 25.30 (λ=620 nm) of the NiO/ZnO/ITO device. We demonstrated the high-performing transparent photodetector by using the multifunctional MoOx window layer.
