Fabrication of p-NiO nanoflakes/n-Si(100) heterojunction architecture for high sensitive photodetectors

We report the facile hydrothermal synthesis of p-NiO nanoflakes (NFs)/n-Si (100) heterojunction architecture and its photoresponse behavior. The vertically grown NiO NFs architecture is clearly seen on the Si substrate, as evidenced from the field emission scanning electron microscopy images. The elemental composition of the grown nanostructure on the Si substrate was estimated using energy-dispersive X-ray spectroscopy, and resonant Rutherford backscattering spectrometry measurements. The grazing incidence X-ray diffraction measurement reveals the grown NiO NFs architecture is of face centered cubic phase. The I-V characteristics of p-NiO NFs/n-Si heterojunction architecture shows good rectifying behavior in the dark and the increased photocurrent in the reverse bias imply the formation of p–n junction at the interface of p-NiO NFs and n-Si substrate. The voltage-dependent sensitivity of the device reveals the highest sensitivity at reverse bias of 3 V. The time-dependent photoresponse measurements of the device show good stability and repeatability under blue light illumination. The response and recovery time of the device is found as 6.18 s and 1.83 s under the reverse bias of 3 V. Our experimental studies demonstrate that the fabricated p-NiO NFs/n-Si heterojunction device has considerable promise for the practical photodetector applications.