Radial heterojunction based on single ZnO-CuxO core-shell nanowire for photodetector applications

Andreea Costas,Camelia Florica,Ionut Enculescu,Nicoleta Apostol,Andrei Nitescu,Nicoleta Preda,Andrei Kuncser

doi:10.1038/s41598-019-42060-w

Andreea Costas, Camelia Florica + Show 5 more

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https://doi.org/10.1038/s41598-019-42060-w

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Journal: Scientific Reports	Publication Date: Apr 3, 2019
Citations: 60	License type: open-access

Affiliation: National Institute of Materials Physics

Abstract

ZnO-CuxO core-shell radial heterojunction nanowire arrays were fabricated by a straightforward approach which combine two simple, cost effective and large-scale preparation methods: (i) thermal oxidation in air of a zinc foil for obtaining ZnO nanowire arrays and (ii) radio frequency magnetron sputtering for covering the surface of the ZnO nanowires with a CuxO thin film. The structural, compositional, morphological and optical properties of the high aspect ratio ZnO-CuxO core-shell nanowire arrays were investigated. Individual ZnO-CuxO core-shell nanowires were contacted with Pt electrodes by means of electron beam lithography technique, diode behaviour being demonstrated. Further it was found that these n-p radial heterojunction diodes based on single ZnO-CuxO nanowires exhibit a change in the current under UV light illumination and therefore behaving as photodetectors.

Highlights

Further it was found that these n-p radial heterojunction diodes based on single ZnO-CuxO nanowires exhibit a change in the current under UV light illumination and behaving as photodetectors
ZnO nanowire arrays were obtained by thermal oxidation in air, the approach being described in our previously papers[13,45]
The field emission scanning electron microscope (FESEM) images at a lower magnification (Fig. S1(a,b)) display that the Zn foil surface is uniformly covered with nanowires arrays

Summary

Introduction

Further it was found that these n-p radial heterojunction diodes based on single ZnO-CuxO nanowires exhibit a change in the current under UV light illumination and behaving as photodetectors. The design and fabrication of nanostructures with complex architectures can fuel the new trends in modern technologies by enabling the development of low dimensional devices with improved performances and additional functionalities In this context, the fabrication of one-dimensional or quasi one-dimensional nanostructures such us semiconductor heterojunctions or metal/semiconductor junctions is an attractive focus point for researchers[1,2,3]. The advantage of such core-shell heterostuctures is related to an enhancement of the charge collection efficiency at the electrodes due to the internal field which appears at the interface between the p-n semiconductors (along the length of the nanowire ~μm range) and the separation of photogenerated charges which takes place along the radius of the nanowire (~nm range)[1,36] Such ZnO-CuO core-shell radial heterojunction nanowires are www.nature.com/scientificreports/. Further these were covered with CuO shells obtained by combining various techniques: electrodeposition with thermal oxidation in an oxygen atmosphere[40], electrophoresis with electroless deposition[41] and sputtering with thermal oxidation in oxygen atmosphere inside the chemical vapour deposition tube furnace[35]

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