Enhanced Optical Properties of ZnO and CeO2-coated ZnO Nanostructures Achieved Via Spherical Nanoshells Growth On A Polystyrene Template

Asmaa Eltayeb,Enda Mcglynn,Stephen Daniels

doi:10.1038/s41598-017-03905-4

Asmaa Eltayeb, Enda Mcglynn + Show 1 more

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https://doi.org/10.1038/s41598-017-03905-4

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Journal: Scientific Reports	Publication Date: Jun 16, 2017
Citations: 4	License type: open-access

Affiliation: Dublin City University

Abstract

In this paper, ZnO, CeO2 and CeO2-coated ZnO nanostructures were synthesised by simple and efficient low temperature wet chemical methods on Si (100) and quartz substrates. The ZnO films were prepared by a drop coating deposition method. This was then combined with a thin layer of the redox active material CeO2 to form CeO2-coated ZnO films. Spherical ZnO nanoshell structures and CeO2-coated ZnO nanoshells have been prepared using polystyrene (PS) sphere monolayer templates. The structural properties and morphologies of the nanostructures were analysed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The nanostructure compositions are studied in more detail using secondary ion mass spectroscopy (SIMS). The optical properties of the nanostructures were measured using ultraviolet-visible (UV-Vis) absorption spectroscopy in order to ascertain the effects of the nanoshell structures and the whispering gallery modes associated with these structures on the optical properties of the deposits. Our data show UV and visible light absorption was very significantly enhanced due to this nanostructuring.

Highlights

Enhanced broadband light absorption by nanostructuring of materials, recently described by Yao et al.1., is considered an important new engineering design parameter for high performance solar cells and protectors
Coated ZnO film (C_Z_F) and CeO2-coated ZnO nanoshell (C_Z_NS), as-deposited and annealed at 500 °C and 800 °C in air for 30 minutes are shown in Supplementary Figures III and IV, respectively
We have demonstrated a simple and reproducible method to fabricate ZnO and CeO2-coated ZnO thin films and functional nanoshell nanostructures on Si (100) and quartz substrates

Summary

Introduction

Enhanced broadband light absorption by nanostructuring of materials, recently described by Yao et al.1., is considered an important new engineering design parameter for high performance solar cells and protectors. Like Li et al.[30], Shen et al.[31] and Deng et al.[32], synthesised ZnO hollow particles using a template-free solution method, template-free evaporation method and template-free sonochemical fabrication method, respectively These proposed methods are described as simple and inexpensive, the drop coating method (proposed by Byrne et al.17, 33) using a template of polystyrene beads, yields samples with a patterned spherical nanoshells of ZnO with improved crystallinity, purity and optical properties. The ZnO layers used to generate ZnO films were prepared by a method initially proposed and demonstrated by Greene et al.[35, 36] and further developed by Byrne et al.[17, 33, 37] This method involves drop coating a mixture of zinc acetate (5 mM) in anhydrous ethanol solution onto the substrate surface for a period of 20–25 seconds before being rinsed with fresh ethanol and dried with a nitrogen stream.

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