Nick (Aagnik) Pant

Univ. of Texas at Austin (Postdoc) ← Univ. of Michigan (Ph.D.) ← McGill Univ. (B.Eng.)  

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My research addresses the grand societal challenge of making our electronics and energy systems sustainable and energy efficient. I use high-performance computing and artificial intelligence to model materials from the atomic to device scales, to better understand the physical mechanisms that lead to heat loss in energy-conversion semiconductor devices.

I have a track record in tackling fundamental engineering challenges through collaborations with experimentalists and industry partners, such as Lumileds, one of industry's most significant and pioneering LED manufacturers. To learn more, read this invited feature article I wrote for Compound Semiconductor.

I am a recipient of the NSERC Postgraduate Scholarship and the MICDE Graduate Fellowship. 

Research Vision

My research addresses the central question: how can computational methods accelerate the design of advanced materials for energy technologies? State-of-the-art quantum methods are limited to modelling materials at the atomic scale; but what about physical phenomena that only emerge at larger length scales? I address this challenge through the paradigm of co-design across length scales, leveraging machine learning to reach previously inaccessible length scales.

Recent Publications

Uncovering energy-loss mechanisms in deep-ultraviolet LEDs

We have developed a theoretical framework to compute non-radiative recombination rates in quantum wells that are used in actual LEDs. This is contrast to previous methods that could only model bulk materials. Our findings uncover the essential role of Auger-Meitner recombination in limiting the efficiency of UV LEDs, essential for manufacturing and healthcare applications.  (Appl. Phys. Lett. 125, 021109 (2024))

Challenging the conventional view on what makes LEDs efficient

By developing a theoretical  framework to assess the impact of disorder on optoelectronic materials, I have challenged a long-standing hypothesis that carrier localization is responsible for the highly efficient nature of nitride LEDs. The takeaway is simple: designs that minimize the defect density acheive high efficiency. (Phys. Rev. Applied 20, 064049 (2023))


Uncovering the origin of the unwanted hue shift of nitride LEDs 

Using multi-scale modelling, I identified the detrimental role of degenerate carrier densities in causing the notorious hue-shift problem of nitride LEDs, where a green LED undesirably becomes blue with increasing current. I also showed that quantitative agreement with experiments requires considering many-body effects that are ignored by most commercial solvers. (AIP Advances 12, 125020 (2022))


Computational discovery of AlN/GaN superlattices for power electronics

Using state-of-the-art density-functional theory and many-body perturbation theory, I have predicted that atomically thin superlattices of AlN and GaN are the most promising technologically viable semiconductors for power devices, based on the modified Balifa figure of merit, because of their ultra-wide band gaps and high electron mobility. Such superlattices can be grown with MBE or MOVPE. (Appl. Phys. Lett. 121, 032105 (2022))


Updates

Recent Collaborators

Industry

Experimentalists

Theorists

A little more about me

Bio

I am currently a postdoctoral fellow, developing many-body methods to understand electron-phonon interactions in semiconductors from first principles, with the aim of designing more efficient materials for transistors, LEDs, and solar cells. During my Ph.D., I developed and applied first-principles and multi-scale quantum methods to improve the performance of nitride semiconductors for LEDs and power electronics. 

Research Journey

My research journey began as an experimentalist in the group of Prof. Zetian Mi, where I grew semiconductor crystals with Molecular Beam Epitaxy to build nitride-semiconductor photocatalysts that produced clean chemical fuels with sunlight. I turned to theory, working with Prof. Emmanouil Kioupakis, to understand the microscopic energy-loss mechanisms in semiconductors that were challenging to study experimentally because they did not have a clear signature. This journey led me to collaborate with industry (Lumileds) and experimental groups (Feezell group at UNM and Rajan group at OSU) as well as theory groups (Van de Walle group at UCSB) to uncover the microscopic loss mechanisms in nitride LEDs. As a postdoctoral fellow with Prof. Feliciano Giustino, I am developing advanced methods to model quasielectron and polaron transport in solids to accurately predict the carrier mobility of semiconductors. This has given me the opportunity to further collaborate with other theory groups (Louie group at UC Berkeley and Li group at USC).

Personal

I was born in Kathmandu, Nepal and I immigrated to North America when I was ten years old (I grew up mostly in Canada, and have lived in nine different cities across the world). As an immigrant, I understand that our socioeconomic backgrounds touch every aspect of our lives. It is because of this that I strongly believe in efforts to promote diversity and equity. In terms of hobbies, I enjoy cycling, hiking, and travelling the world, and I am a big fan of languages and linguistics. In addition to English, I speak Nepali, and a little bit of Hindi and French. My favourite movie is Timecrimes, an independent and underrated Spanish movie that is hilarious and bound to give you some great laughs.