Atom probe microscopy of zinc isotopic enrichment in ZnO nanorods

C N Ironside,S M Reddy,C Gray,N A Marks,W D A Rickard,D W Saxey,E Mcglynn

doi:10.1063/1.4976299

Abstract

We report on atomic probe microscopy (APM) of isotopically enriched ZnO nanorods that measures the spatial distribution of zinc isotopes in sections of ZnO nanorods for natural abundance natZnO and 64Zn and 66Zn enriched ZnO nanorods. The results demonstrate that APM can accurately quantify isotopic abundances within these nanoscale structures. Therefore the atom probe microscope is a useful tool for characterizing Zn isotopic heterostructures in ZnO. Isotopic heterostructures have been proposed for controlling thermal conductivity and also, combined with neutron transmutation doping, they could be key to a novel technology for producing p-n junctions in ZnO thin films and nanorods.

Highlights

The study of isotopically enriched semiconductors has revealed novel physics because it provides a means of separating the contribution of the phonons and the electronic band structure to the physical properties of a material, including the optical, electrical and thermal properties.[1,2] ZnO has been extensively investigated,[3] partly because its large exciton binding energy offers the possibility of efficient light emitting devices if a p-doping technology can be reliably implemented
In naturally abundant natZnO, 18% of the Zn is 68Zn and when this isotope absorbs a neutron it is transmuted into Ga which could act as a donor impurity
Another device possibility includes engineering the thermal conductivity of ZnO nanorods by using an isotopic superlattice to reduce the thermal conductivity, whilst maintaining the electrical conductivity, and thereby improving the thermoelectric figure of merit.[9]

Summary

Introduction

The study of isotopically enriched semiconductors has revealed novel physics because it provides a means of separating the contribution of the phonons and the electronic band structure to the physical properties of a material, including the optical, electrical and thermal properties.[1,2] ZnO has been extensively investigated,[3] partly because its large exciton binding energy offers the possibility of efficient light emitting devices if a p-doping technology can be reliably implemented. Atom probe microscopy of zinc isotopic enrichment in ZnO nanorods A. Marks1 1Department of Physics and Astronomy, Curtin University, Bentley, Perth, 6102 WA, Australia 2Geoscience Atom Probe, Advanced Resource Characterisation Facility, John De Laeter Centre, Curtin University, Building 301, Bentley, WA 6102, Australia 3School of Physical Sciences, National Centre for Plasma Science and Technology, Dublin City University, Glasnevin, Dublin 9, Ireland 4Department of Applied Geology, Curtin University, Bentley, WA 6102, Australia (Received 18 December 2016; accepted 30 January 2017; published online 8 February 2017)

Results

Conclusion