Hot off the press! Prakriti’s second paper as a PhD student, and my first one with an experimental collaborator: High Temperature Equilibrium of 3D and 2D Chalcogenide Perovskites. We consider all competing phases in the Ba-Zr-S system and predict that the Ruddlesden Popper phases are likely to form during high temperature synthesis. This is confirmed experimentally via XRD and Raman, with our database of Raman specta used to eliminate the possibility of other phases forming.
New pre-print on ArXiv: Steric engineering of point defects in lead halide perovskites. This is an idea I have been working on since early 2020 (how time flies); namely, translating the concept of reorganisation energy from organic materials to inorganic and hybrid organic-inorganic materials. In the context of organics it is used to engineer for particular charge transport properties. In this work I propose it can be used to engineer charge trapping / de-trapping rates at point defects in crystalline materials which display large lattice relaxation. I also show that the usual defect classification of “deep”, “inactive” and “shallow” is not so relevant in these materials. For accurate predictions I had to interpolate along atomic translations and molecular rotations; I have released the code that implements this here. Thoughts and feedback on any and all are very welcome.
New term, new teaching! We have developed a new Quantum Optics course for 3rd year undergraduates on the physics programme. As a newbie to quantum optics, learning about MEEP has been a pleasure. We also have a nice Microsoft Azure setup for the students to use. Takes the pain out of installation, and the students can run it from any device with a browser and terminal.
Our latest work developed alongside experimental collaborator Giulia Longo (and others) is now available on the pre-print server ArXiv. We consider all competing phases in the Ba-Zr-S system and predict that the Ruddlesden Popper phases are likely to form during high temperature synthesis. This is confirmed experimentally via XRD and Raman, with our predicted Raman specta for all phases used to eliminate the possibility of other phases forming.
Myself and Prakriti are heading to Boston for MRS Fall. I’ll be presenting my latest results analysing the quantum mechanics of non-radiative carrier capture processes in mixed A-site cation perovskites. Prakriti will be presenting her work modelling the vibrational spectra of chalcogenide perovskites.
Deep in the autumn teaching term now. Still some time to update our ThermoPot repository, which will hopefully be fully tested and available for wider use in the next few months…
Yay! I’ve completed my induction period at Northumbria, and have been promoted to an Assistant Professor position :)
I’ll be speaking on a panel at the UK Research Software Engineering conference next week. We will be discussing “Developing the necessary skills to support the future of computational research” - something I’ve thought a fair bit amount since teaching Computational Physics at undergraduate level. Looking forward to meeting up with the very friendly RSE-crowd.
Very pleased to be speaking about A-site cation mixing and non-radiative carrier trapping at a special meeting celebrating 10 years of the Material Design Group at Imperial. Great to see some old faces - just wish I could have been there in person..
Our review paper “Modelling interfaces in thin-film photovoltaic devices” is out in Frontiers in Chemistry. A new collaboration with Newcastle (Toon) based scientists from Northumbria University and Newcastle University.
I’m officially a Fellow of the Higher Education Academy - this means I have attained the standards defined the UK Professional Standards Framework for teaching in higher education. You can find the reflective essay I wrote for my application here.
Today my good friend David Mytton visited Northumbria to talk about Software engineering tools, sustainability, and academia. An excellent turn-out from Northumbria students and staff, with staff from the Newcastle RSE team joining us also. Nice to start building RSE connections in the North-East.
Prakriti is presenting a poster “Following the reaction: computational spectroscopy of perovskite BaZrS3” at the Institute of Physics' Advances in Photovoltaics conference today. This is a warm-up project, building on Prakriti’s existing expertise in lattice dynamics, to kick start her PhD work. Of course, the warm-up is turning into more of a work-out as we start to uncover more and more tempting science…
We are putting the final touches on our review paper “The Physical Significance of Imaginary Phonon Modes in Crystals”. Imaginary modes have a bad reputation (“your crystal is all wrong!") but they can contain a lot of useful physics - and in this review article we tell you how to access all that juicy information on phase transitions and dynamical disorder.
January has been the Month of Marking *sigh*.
A pleasant end of year activity has been writing my application for fellowship of the Higher Education Academy. It has been a chance to reflect on my teaching this term. It has also encouraged me to read two excellent books: Teaching Tech Together by Greg Wilson and Small Teaching by James M. Lang.
I’m coming to the end of teaching a Theory and Computation course to second year Physics students at Northumbria. It’s been a learning curve for all involved, and I’ve got improvements up my sleeve for next year’s iteration - including an automated Github-based workflow for monitoring student progress. Now I’m looking forward to the rest over Christmas and a more research-intensive new year!
A big welcome to Prakriti who is joining us as a PhD student to work on energy materials modelling as part of the CDT-ReNU. Her project will focus on modelling battery cathode materials in the spinel structure, but first we are taking a little de-tour into chalcogenide perovskites.
SeptembRSE has been running throughout this month, with a very full timetable of RSE-related talks (RSE = Research Software Engineering). I’m speaking today about the importance of, and practicalities around, publishing your code in a peer-reviewed journal like JOSS or JORS.
If you are a software developer then you better run and hide - I’ve joined the editorial board of the Journal of Open Source Software (JOSS) and will be pinging you for reviews soon. JOSS is a journal of the future - with a peer review process that is fully transparent (using Github issues) and designed to improve the quality of software submitted. I’ll be talking more about JOSS at the SeptembRSE conference.
Today I’m speaking about our latest paper “Giant Huang-Rhys Factor for Electron Capture by the Iodine Interstitial in Perovskite Solar Cells” at the 15th International conference on materials chemistry (MC15). For those that couldn’t attend you can find a recording of the same presentation here.
I’m pleased to say that our paper “Giant Huang-Rhys Factor for Electron Capture by the Iodine Interstitial in Perovskite Solar Cells” has been published open-access in the Journal of the American Chemical Society.
A pre-print for our new paper “Giant Huang-Rhys Factor for Electron Capture by the Iodine Interstitial in Perovskite Solar Cells” is available on arXiv. In this paper we analyse the quantum mechanics of carrier trapping at an abundant defect in the prototype hybrid perovskite “MAPI”. Our main finding is that there is large lattice relaxation after carrier capture, leading to a Huang-Rhys factor (a proxy for electron-phonon coupling) exceeding 300 and fast electron capture. This suggests that suppression of the large octahedral rotations associated with the lead-iodide cage is an important factor to enhance photovoltaic performance.
Next week (14/4) I’m speaking at the Institute of Physics conference “Lessons Learnt in Lockdown: Teaching computational physics in 2020 and beyond”. I’ll introduce the pedagogy used in Software Carpentry lessons, and reflect on a carpentry-based workshop I have delivered both in and out of lockdown, Python for Physicists. Software Carpentry takes inspiration from the world of open-source software, developing lesson materials collaboratively and making them available for anyone to re-use, adapt and extend. I dream of a future where most university education is developed and delivered in a similar way…
We’ve just released a new version of effmass with support for FHI-aims calculations. Thanks to Matthias Golomb for contributing the necessary code. Castep is next, watch this space. UPDATE: effmass 2.0.0 supports Vasp, Castep, FHI-aims and ASE. It also comes with a command line interface..
16th February Welcome to Kiran and Kishore, who are working with me as part of the Electrical Engineering Advanced Practice programme at Northumbria. They will be using the SMACT software package to screen for new spinel compounds.
17th January I’m now a full member of the Materials Chemistry Consortium. What does this mean? That I (and other member of NUPV) can apply for computer time on the Archer2 and Young supercomputers - let’s get diagonalising..
1st December Work with me! A funded PhD is available - for more information please see the Group page.
23rd November I’m preparing to deliver my first online teaching session, and first time teaching as a faculty member. It’s a course I’m familiar with (Programming in Python, adapted from the Software Carpentry course), but I’m wondering how well the “live coding” approach will work: me talking + screenshare with the code I am typing + students' jupyter notebook + chat window / website / other useful course materials seems a lot for a small laptop screen…
10th November I’ll be delivering a seminar at the University of Oklahoma Centre for Quantum Research and Technology this Friday (13th November). I’ll be talking about nonparabolic effective mass, and the effect this has on the optical and transport properties of photovoltaic materials - the corresponding paper is here.
1st October It’s my first day back from maternity leave. I’m thinking about my strategy for the next three years, writing applications for computer time and (virtually) meeting with my new colleagues at Northumbria University. Pleased to be back on board.
31st July Our quick-start guide for first-principles modelling of point defects has been published in JPhys Energy. The paper is Open Access and available here.
1st June Today is my first official day as a Vice-Chancellor’s fellow at Northumbria University. I’m on maternity leave until October, but happy to stop thinking about baby Robin for a little while and attend the online induction events. With lots of events moving online it’s been easy for me to keep a toe in the academic waters.
12th March Our CarrierCapture.jl software has been accepted for publication with the Journal of Open Source Software. The accompanying paper can be found here.
17th March I have been awarded the Thomas Young Centre at Imperial prize: “An annual award to the student who has demonstrated the most important and innovative contribution to research in the Theory and Simulation of Materials”. A special thanks to the Walsh group post-docs who worked with and supported me through my PhD (including Jarvist Frost, Jonathan Skelton, Sunghyun Kim, Ji-Sang Park and Samantha Hood). I think the prize money should be spent on thousands of Lindt Lindor chocolates.
13th January I have been awarded the degree of Doctor of Philosophy! It’s been the most productive four years of my life, and very enjoyable to boot: a huge thanks to my supervisor Prof. Aron Walsh and his team at Imperial College London.
1st January I’m currently on maternity leave until October 2020 - wish me luck!
25th November I’m happy to announce that I will be joining Northumbria University as a Vice-Chancellor’s fellow in the department of Mathematics, Physics and Electrical Engineering, and aligned with the EPSRC Centre for Doctoral Training in Renewable Energy Northeast Universities. I’m very excited to see what future research projects and collaborations will bring!
14th November Today I’m teaching version control using Git at Imperial College London. It’s fully booked but you can follow the material yourself using the course webpage which is here and the slides which are here.
5th October From the 5th October until the 9th of November I will be visiting the Laboratory for Materials and Structures at the Tokyo Institute of Technology. We hope to develop software for the high-throughput calculation of non-radiative recombination rates, and builds on the CarrierCapture software developed by the Walsh group at Imperial.
1st October From the 5th of October 2019 until the 26th of January 2020 DotSpace will be exhibited at the Herbert Art Gallery and Museum, The Row Gallery and Leamington Spa Art Gallery and Museum as part of the Coventry Biennial. To accompany the exhibition I am developing a DotSpace web app (aka The Grain Generator) so that visitors can generate their own DotSpace picture - the web app can be found here. More information about the exhibition can be found here.