Laser ablation fabrication of a p-NiO/n-Si heterojunction for broadband and self-powered UV-Visible-NIR photodetection

Authors: Savita Chaoudhary, Avijit Dewasi, Ram Prakash S, Vipul Rastogi, Rui N Pereira, Alessandro Sinopoli, Brahim Aïssa and Anirban Mitra

Journal: Nanotechnology

Date: January 01, 2022

DOI: https://doi.org/10.1088/1361-6528/ac5ca6

Abstract

We report on the optoelectronic characteristics of p-NiO/n-Si heterojunction photodiodes for broadband photodetection, fabricated by depositing a p-type NiO thin film onto a commercial n-type silicon substrate using pulsed laser deposition (PLD) technique. The structural properties of the PLD-grown p-NiO material were analysed by means of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), confirming its crystalline nature and revealing the presence of Ni vacancies, respectively. Hall measurements confirmed the p-type semiconducting nature of the NiO thin film having a carrier concentration of 8.4 × 1016 cm-3. The current-voltage (I-V) characteristics of the p-NiO/n-Si heterojunction photodevice were investigated under different wavelengths ranging from UV to NIR. The self-bias properties under different illuminations of light were also explored systematically. Under self-bias condition, the photodiode exhibits excellent responsivities of 12.5 mA.W-1, 24.6 mA.W-1 and 30.8 mA.W-1 with illumination under 365 nm, 485 nm, and 850 nm light, respectively. In addition, the time dependency of the photoresponse of the fabricated photodevice has also been investigated and discussed thoroughly.