Optimisation of resonant tunnelling diodes for terahertz applications

Watt, Adam Peter (2026) Optimisation of resonant tunnelling diodes for terahertz applications. PhD thesis, University of Glasgow.

Abstract

Resonant Tunnelling Diodes (RTDs) are a prominent technology in THz emitter research. This thesis explores the suitability of these devices for future adoption as THz emitters, primarily focusing on communications applications. Through the establishment of a more accessible fabrication process, critical analysis of the literature, and a systematic analysis of RTD epitaxial structures, some of the challenges of realising these devices in practice have been addressed.

For mass manufacturing capabilities in the future, the RTD fabrication process must be as time and cost-effective as possible while still delivering high-performance devices. A process is developed here with this in mind, keeping the number of steps to a minimum, and using commonly available tools and chemicals to make this process as accessible as possible. High current density RTD devices are fabricated and electrically characterised with this process.

The predictability of RTD device performance will be a key aspect of future designs. Establishing reliable figures of merit to characterise device performance and designing devices to achieve these figures of merit, will be key to producing RTDs for a range of applications. A critical analysis of results from the literature is performed to detect trends in device performance and, using the IRE, comparisons of these historical devices are made. The IRE allows for optimisation of the electrical characteristics of the device. An investigation into the effects of the epitaxial structure on the device performance is also done.

For optimisation of RTD devices, the epitaxial structure requires close examination. A systematic analysis is performed, with small changes made to key epitaxial parameters – including the thicknesses and positions of active layers – resulting in a clearer perception of the effect these parameters have on the device performance. Comparisons with literature and simulation work are done, and conclusions about the epitaxial optimisation of RTD devices are formed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > TA Engineering (General). Civil engineering (General)
• Colleges/Schools: College of Science and Engineering > School of Engineering
• Funder's Name: Engineering and Physical Sciences Research Council (EPSRC)
• Supervisor's Name: Wasige, Professor Edward, Hogg, Professor Richard and Kelly, Professor Anthony
• Date of Award: 2026
• Depositing User: Theses Team
• Unique ID: glathesis:2026-85924
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 May 2026 10:40
• Last Modified: 20 May 2026 11:58
• Thesis DOI: 10.5525/gla.thesis.85924
• URI: https://theses.gla.ac.uk/id/eprint/85924

Related URLs

• Conference proceeding
• Article DOI
• Conference item