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Updated: Sep 23, 2025

Developing High Performance GaP/Si Heterojunction Solar Cells
Published on: November 16, 2018
Negative-capacitance and bulk photovoltaic phenomena in gallium nitride nanorods network
Atul Thakre1,2, Sunil Singh Kushvaha1,2, M Senthil Kumar1,2
1Academy of Scientific and Innovative Research (AcSIR), CSIR-National Physical Laboratory Campus Dr. K. S. Krishnan Marg New Delhi 110012 India ashok553@nplindia.org.
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.
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