Atić, A., Wang, X., Vuković, N. et al. (4 more authors) (Cover date: February-2 2024) Resonant tunnelling and intersubband optical properties of ZnO/ZnMgO semiconductor heterostructures: impact of doping and layer structure variation. Materials, 17 (4). 927. ISSN 1996-1944
Abstract
ZnO-based heterostructures are up-and-coming candidates for terahertz (THz) optoelectronic devices, largely owing to their innate material attributes. The significant ZnO LO-phonon energy plays a pivotal role in mitigating thermally induced LO-phonon scattering, potentially significantly elevating the temperature performance of quantum cascade lasers (QCLs). In this work, we calculate the electronic structure and absorption of ZnO/ZnMgO multiple semiconductor quantum wells (MQWs) and the current density–voltage characteristics of nonpolar m-plane ZnO/ZnMgO double-barrier resonant tunnelling diodes (RTDs). Both MQWs and RTDs are considered here as two building blocks of a QCL. We show how the doping, Mg percentage and layer thickness affect the absorption of MQWs at room temperature. We confirm that in the high doping concentrations regime, a full quantum treatment that includes the depolarisation shift effect must be considered, as it shifts mid-infrared absorption peak energy for several tens of meV. Furthermore, we also focus on the performance of RTDs for various parameter changes and conclude that, to maximise the peak-to-valley ratio (PVR), the optimal doping density of the analysed ZnO/Zn₈₈Mg₁₂O double-barrier RTD should be approximately 10¹⁸ cm⁻³, whilst the optimal barrier thickness should be 1.3 nm, with a Mg mole fraction of ~9%.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
Keywords: | wide-bandgap oxide semiconductors; resonant tunnelling; intersubband transitions; depolarisation shift |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Pollard Institute (Leeds) |
Funding Information: | Funder Grant number EPSRC (Engineering and Physical Sciences Research Council) EP/T034246/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 07 Feb 2024 14:36 |
Last Modified: | 23 Jan 2025 16:03 |
Status: | Published |
Publisher: | MDPI |
Identification Number: | 10.3390/ma17040927 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:208843 |