Cónal Murphy
Runner-Up
What encouraged you to submit your application to the 2023 Postgraduate Research Publication of the Year?
I am a member of the Photonics Theory Group, Irish Photonic Integration Centre (IPIC), SFI Centre for Photonics at Tyndall and the senior members of the group continually encourage all students to put themselves forward for these types of awards. A member of our research group, Dr Cara-Lena Nies, is a former winner of the award and spoke highly of her involvement in the past.
What inspired you to choose the subject of your paper?
Devices operating in the mid-infrared have a wide array of sensing applications across industrial, agricultural, medical, environmental and defence sectors. Prototype inter-band cascade LEDs based on InAs/GaSb superlattices developed in Lancaster University, UK had previously demonstrated promise for these applications and following conversations with experimental collaborators in Lancaster, we decided to carry out a theoretical investigation of this material system.
What’s your paper about and how did you prepare for it? What role did research excellence play in your approach?
In our paper we elucidate the origin of impressive radiative performance in InAs/GaSb superlattice inter-band cascade LEDs. We provide detailed insight into the impact of carrier localisation, miniband formation, optical selection rules and band filling on the radiative recombination rate. We then carry out highthroughput calculations to identify the scope to increase radiative recombination at fixed peak emission wavelength. Research excellence played a role in this work as, to our knowledge, for these structures prior to this research there had not been (i) detailed discussion of the explicit role played by various aspects of the underlying electronic structure in determining the radiative recombination rate and its temperature dependence or, (ii) in silico optimisation of the radiative recombination rate as a function of emission wavelength. We also provided detailed analysis of spurious solutions as well as other technical details.
The selection for Research Publication of the Year is extremely competitive. What is your advice for those aspiring for nomination next year?
I would encourage all those interested in taking part to take note of reviewers comments that are provided in the review process when submitting an article for publication which can offer a wider perspective on the impact and novel nature of your research. I would also encourage students to use the submission process for the awards as an opportunity to reflect on your research. I feel that it offers a chance to frame and better understand your achievements and development during your research project.
What is the single most significant support Tyndall has been able to offer you in achieving your research goals?
The single most significant support received in carrying out the research associated with the publication was provided by my supervisors, Prof. Eoin P. O’Reilly and Dr Christopher A. Broderick. Their assistance in the theoretical and technical aspects of this research was fundamental in the completion of the work and the subsequent publication.
Cónal Murphy, Eoin P O’Reilly and Christopher A Broderick, ‘Theory and optimisation of radiative recombination in broken-gap InAs/GaSb superlattices’, Journal of Physics D: Applied Physics 57 035103.