TY  - UNPB
TI  - Advanced Laser Processing of Diamond for Robust Electronics
EP  - 183
AV  - public
Y1  - 2025/01/28/
N1  - Copyright © The Author 2025. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author?s request.
ID  - discovery10203618
N2  - The aim of this thesis is to advance the field of diamond electronics for applications in harsh-environments by utilising a novel femto-second laser writing process. This technique allows for complex, three-dimensional architectures of electronically active material to be drawn into the diamond bulk. The properties of the resulting nano-carbon networks (NCNs) can be tuned by varying the laser parameters, such as the pulse repetition rate and translational write speed. In this work, highly conducting, highly resistive and even semiconducting NCNs are reported. This project has covered both structural and electronic characterisation of this material, as well as the fabrication and testing of functional all-carbon diodes and field-effect transistors.

Structural investigation of the NCNs was performed using a scanning tunnelling electron microscope, able to resolve their crystal structure down to the individual atoms. This work highlighted the unique lattice arrangements created by each set of laser parameters, as well as the variation in the internal structure towards the substrate?s surface. Notably, the carbon phase ?diaphite?, previously found exclusively in meteorite samples, was a identified. This work has been published in ACS Nano, and has exciting prospects in both material science and astrogeology.

The electronic characterisation, carried out using current-voltage analysis and impedance spectroscopy, captured distinct behaviours arising from a number of tested laser parameters. These ranged from simple conductive tracks, which allow for internal circuitry and true vertical device architectures, to semiconducting material displaying asymmetric voltage barriers.

Following on from these discoveries, discrete all-carbon electronic devices were fabricated and tested, including tuneable diodes and field-effect transistors. These devices are the first of a planned all-carbon electronics suite, which will have significant impact in applications in extreme environments due to diamond?s unique durability and performance.
UR  - https://discovery.ucl.ac.uk/id/eprint/10203618/
PB  - UCL (University College London)
M1  - Doctoral
A1  - Henderson, Calum Stewart
ER  -