Carrier transport modelling in group-IV SiGeSn quantum well semiconductor lasers

Large-scale optoelectronics integration is limited by inability of conventional group-IV semiconductors (silicon and germanium) to be efficient light emitters, because of their indirect bandgap. In recent years a big advance has been made in this direction by successful demonstration of lasing in germanium-tin alloys, which can be direct bandgap semiconductors. This first working group-IV laser was optically pumped, and had a limited operation temperature, only up to T < 90 K. Further developments have increased the maximum operating temperature up to 270 K with optical pumping, and electrically pumped lasing up to 110K has also been demonstrated. Direct-bandgap group IV materials may therefore represent a pathway towards monolithic integration of group-IV based photonics and CMOS technology. Important further developments on this route would be electrically pumped laser operating at room temperature. A way forward could be to use multiple quantum well (MQW) structures, which have improved very much the performance of III-V based lasers. In this project the carrier transport in MQW laser structures will be considered, to describe the carrier trapping in quantum wells, or escape into other wells or into continuum. <br /> <br /> The aim will be to achieve a reasonably homogeneous distribution of electrons and holes across the MQW structure. The general methodology is described in the literature on III-V semiconductor based MQW lasers, but will here be used, with appropriate modifications, for group-IV materials. The electronic structure of SiGeSn based MQWs, necessary for transport modelling, will be calculated using the already developed codes. The overall target would be to find good choices for the wells and barriers, or even their shapes, to deliver a good carrier distribution, accounting for practical constraints in the material composition of SiGeSn alloy which can actually be grown. Based on that, structures which are optimal, or at least good enough to be prospective, will be designed for laser operation at room temperature.

<p>Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. Please state clearly in the Planned Course of Study section that you are applying for <em><strong>EPSRC DTP Engineering & Physical Sciences</strong></em> (if you do not apply to this programme code, your application will not be considered) in the research information section that the research degree you wish to be considered for is <em><strong>Carrier transport modelling in group-IV SiGeSn quantum well semiconductor lasers</strong></em> as well as <a href="https://eps.leeds.ac.uk/electronic-engineering/staff/226/dr-zoran-ikonic">Dr Zoran Ikonic</a> as your proposed supervisor. <em><strong>Please state clearly in the Finance section that the funding source you are applying for is School of Electronic & Electrical Engineering Studentship 2025/26.</strong></em></p> <p>If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p> <p>Applications will be considered after the closing date.  Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application.  We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed.</p> <p>Please note that you must provide the following documents in support of your application by the closing date of 31 January 2025:</p> <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement and Research Proposal</li> <li>CV</li> </ul>

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<p class="MsoNoSpacing" style="text-align:start; margin-bottom:24px">A highly competitive EPSRC Doctoral Landscape Award providing full academic fees, together with a tax-free maintenance grant at the standard UKRI rate (£19,237 in academic session 2024/25) for 3.5 years.  Training and support will also be provided.</p> <p>This opportunity is open to all applicants.  All candidates will be placed into the EPSRC Doctoral Landscape Award Competition and selection is based on academic merit.</p> <p><strong>Important:</strong> Please note that that the award does <strong><em>not</em></strong> cover the costs associated with moving to the UK.  All such costs (<a href="https://www.leeds.ac.uk/international-visas-immigration/doc/applying-student-visa">visa, Immigration Health Surcharge</a>, flights etc) would have to be met by yourself, or you will need to find an alternative funding source. </p> <p>Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.</p>

<p>For further information about this project, please contact Dr Zoran Ikonic by email to <a href="mailto:EMAIL@leeds.ac.uk">Z.Ikonic@leeds.ac.uk</a></p> <p>For further information about your application, please contact PGR Admissions by email to <a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a><br />  </p> <p> </p>