Macquarie University
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Low-temperature processing of porous zinc-oxide for flexible sensing applications

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posted on 2022-11-10, 03:55 authored by Jeff Huang

Three-dimensional nanostructured networks are proposed as a means of substantially improving functional materials through a combination of maximised surface area, and exceptional morphological connectivity. The formation of nanoscale junctions (i.e., primary bonds) between constituent nanostructures facilitates tremendous enhancements to interfacial conductivity and structural integrity, thereby offering magnitudes of improvement over the pristine morphologies formed by weak Van der Waals contacts. However, integration with temperature sensitive polymers, and thin metal electrodes in wearable devices preclude the use of conventional approaches such as thermal sintering. This work investigates the use of solvent vapour as a low-temperature means of rapidly eliciting high-quality nanojunctions in highly porous zinc-oxide nanoparticle networks. The proposed method is an effortless, inexpensive, and easily scalable processing strategy, capable of generating interparticle necking in the matter of minutes. In testing as a UV photodetector at a low operation bias of 1 V, the vapour enhanced network produced a 128,000-fold improvement in responsivity (20.6 A/W at 365 nm, 1 μW/cm²) over the pristine structure, and a 5300-fold improvement over a thermally produced network; meanwhile maintaining exceptionally low dark currents (~143 pA). The low temperature synthesis and exceptional performance further suggest high potential adaptability of this material as a wearable UV sensor.


Table of Contents

1. Introduction -- 2. Background -- 3. Materials and methods -- 4. Results and discussion -- 5. Conclusions and future work -- References -- Appendix I - Comparison between TA300 and VA5 -- Appendix II - TEM nanoparticle size analysis


A thesis submitted to Macquarie University for the degree of Master of Research

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


Thesis MRes, Macquarie University, School of Engineering, 2022

Department, Centre or School

School of Engineering

Year of Award


Principal Supervisor

Noushin Nasiri


Copyright: The Author Copyright disclaimer:




68 pages