eV me = 1.2 m0 mh = 0.4 m0 εr = 37 BiSeI Eg ind = 1.52 eV me = 0.5 m0 mh = 0.3 m0 εr = 36 Small effective masses and large dielectric constants J. Mater. Chem. A 4, 2060–2068 (2017)
How to explain experimental results? – Large Stokes shift in many materials w. deep defects – Subpicosecond decay characteristic of self-trapping (TA experiments suggest >10 ps) – TA signal persists to high carrier densities – could be photoinduced absorption or large trap density ACS Ener. Lett. 7 2954–2960 (2022) Conclusion: self-trapping unlikely!
candidate materials do exist Hard work needed to optimise properties (cannot expect same rate of progress as MAPbI3 ) A simple screening of electronic properties without including defect chemistry is not good enough!
– Dr Keith Butler (Bath) – Dr Jarvist Frost, Prof. Aron Walsh (Imperial) Compute Resources – Legion & Grace (UCL) – ARCHER (UK) And you for your attention!