Negative-capacitance and bulk photovoltaic phenomena in gallium nitride nanorods network. Issue 57 (21st September 2018)

• Record Type: Journal Article
• Authors: Thakre, Atul; Kushvaha, Sunil Singh; Kumar, M. Senthil; Kumar, Ashok
• Is Part Of: RSC advances. Volume 8:Issue 57(2018)
• Page Start: 32794
• Page End: 32798
• Publication Date: 2018-09-21
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra06101g
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : An enhanced self-powered near-ultraviolet photodetection phenomenon was observed in epitaxial gallium nitride (GaN) nanorod networks grown on an intermediate layer of N:GaN on a nitridated HfO2 (N:HfO2 )/SiO2 /p-Si substrate. Abstract : An enhanced self-powered near-ultraviolet photodetection phenomenon was observed in epitaxial gallium nitride (GaN) nanorods network grown on an intermediate layer of N:GaN on a nitridated HfO2 (N:HfO2 )/SiO2 /p-Si substrate. The fabricated Au/GaN/N:GaN/N:HfO2 /Ag heterostructure exhibited a giant change (OFF/ON ratio > 50 without applying any external electrical field) in its conductance when illuminated by a very weak (25 mW cm −2 ) near-UV monochromatic light with a low dark current (nearly 20 nA). The presented near-UV photodetector offers photoresponsivity of ∼2.4 mA W −1 at an applied voltage of 1 V. We observed an optically generated internal open circuit voltage of ∼155 mV and short circuit current ∼430 nA, which can be attributed to the quantum confinement of free charge carriers in the nanorod matrix. Interestingly, it also shows a negative capacitance after near-UV illumination. It has great potential as a self-powered UV photodetector and in metamaterial applications.