Dr Max Birkett

Personal Statement

Motivated by Physics' potential to transform society, I completed my MPhys Theoretical Physics at Liverpool in 2012 - receiving the Fröhlich Prize for special merit in theoretical physics; my master's project studied quantum entanglement physics and applications. My PhD at the Stephenson Institute for Renewable Energy (awarded 2016) investigated optical properties in emerging thin-film photovoltaic absorbers: in particular, reviewing and developing consistent spectral inversion methods. I'm also a senior software engineer, with a decade's expertise in leading highly-talented, interdisciplinary teams though design and development of major data-critical web, phone, and stand-alone applications for local government, NHS, and corporate clients.

More recently, my studies have sought new high performance, earth-abundant, or low cost functional materials: including solar cell absorbers and high-mobility transparent conducting oxides. Since 2019, I've developed high-throughput workflows seeking computational discovery of metal-organic frameworks (MOFs) for gas separation and catalysis at the Materials Innovation Factory. MOFs are exciting porous crystals comprising metal clusters with organically-bonded polymeric linkers. Their tailorable crystal pore sizes allow enormous effective surface areas (as much as 10,000 m²/g) and myriad applications, e.g. fluid separation/purification, air depollution, catalysis, carbon capture, gas storage, batteries, medicine delivery, and chemical sensing.

Consulting closely with collaborators, my current work features physical modelling/analysis, software development, and rigorous community-tool source code verification. As our group screens many hundred thousand potential crystals - and fully processing each may take several days - one example of how we've dramatically boosted workflow performance is by parallelising calculations across multiple computational nodes or high performance computing (HPC) clusters.

My prior research featured optoelectronic, structural, and theoretical investigations seeking benefical solar cell power-conversion efficiencies and architectures: via studies of emerging absorber band gaps, fundamental gap types, mid-gap states, and dielectric spectra (i.e. refractive index and absorption spectra), using various optical spectroscopies (e.g. Fourier-transform infrared (FTIR), UV-vis, Raman, photoreflectance/modulation, and ellipsometry), supplemented with transport investigations of majority carrier types, densities, mobilities, and conductivities. Structural examinations via x-ray diffraction (XRD) assess phase purity, polycrystalline textures, and any structural disorder in, e.g. space group, lattice parameters, atomic positions, or occupancies (structure factor). Cryogenic spectroscopy gives further insights: as band gap temperature-dependence can impact solar cell efficiencies at operational temperatures (by as much as ~0.1% per °C), while excitonic interactions revealed at low-temperature may either beneficially boost absorption strength (at all temperatures), or detrimentally impact photovoltaic electron-hole extraction.

I'm experienced in computing material properties such as band structures or wavefunction symmetries in density-functional theory (DFT) via ABINIT, but also collaborate with first-principles specialists to evaluate extensive VASP-derived HSE06 supercell calculations: which broadly assess the crystal defect population as a function of growth environment, and the impact of these defects on solar cell or transparent conductor performance - rather important as defects kill solar cell efficiencies.

I'm very happy to discuss ideas further, collaborate in research (not exclusively on the above topics), counsel prospective or current students, arrange school visits/activities, or to help with general queries on physics, photovoltaics, transparent conductors, renewable energy, or software development. If you have a question, please get in touch.