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I think inverse design of materials is a fascinating challenge. This is not just about AI or automation but also about building up new fundamental insights that will guide the design of next-generation technologies. Defect tolerance is an especially exciting area and could offer a new route to achieve efficient semiconductor devices manufactured using cost-effective methods. The past decade of work on defect tolerance in metal-halide perovskites has opened up many questions, and unravelling the links between the many complex factors that influence how defects could be tolerated in materials is an important challenge for the field.

The biggest challenge was securing the first academic position and building up a research group. I first became a PI through the Royal Academy of Engineering Research Fellowship, which I initially held at Cambridge. As a new PI, two of the biggest questions are: 1) how does one create a unique research platform that is recognised as distinct from those of previous supervisors, and 2) how does one compete for bright students in an environment with many other high-profile and well-established PIs? Fortunately, I was in a supportive environment and working across two ‘supergroups’ – the Optoelectronics Group and the Device Materials Group in Cambridge. These supergroups are comprised of multiple PIs, and I was able to use the shared equipment to conduct independent research. At the same time, the highly collaborative and supportive environment provided a vibrant ‘ecosystem’ for PhD students to thrive in, and this helped to attract talented students to work with me. After establishing a track record as an independent PI, it is always much easier to build up the research group. Getting started is always the hardest part.

A highly collaborative and supportive research environment, where people are actively working together to solve problems together and discuss science in an open way.

Bismuth is next to lead on the periodic table and has very similar physical and electronic properties, but unlike lead, it is nontoxic. As such, bismuth-based compounds are appealing for developing electronic analogues to lead-halide perovskites with the aim of replicating the exceptional optoelectronics properties of these materials, but overcome their stability and toxicity limitations.

Bismuth is also the heaviest element that is not radioactive. This makes bismuth-based compounds, such as BiOI, highly appealing for radiation detectors since the attenuation of ionising radiation depends on the average atomic number raised to the fourth power. We have demonstrated that BiOI requires lower thicknesses than industry-standard materials to attenuate sufficient radiation, which reduces the required transport distances that charge carriers need to be transported over, which contributes to the ability of these materials to very sensitively detect low dose rates of radiation. This can lead to X-ray detectors that make medical imaging safer by reducing the required X-ray dose that the patient is exposed to.