For enquires about the group please contact:
Prof Michael B. Johnston (group leader), M.Johnston@physics.ox.ac.uk
Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom.
Xia et al. J. Phys-Mater., 4:044017 (Oct 2021)
[
pdf ][ DOI:10.1088/2515-7639/ac22b9 ] We observed the shift of phonon modes in thin file and single crystals MAPbI3 that occurs when the materials are optically excited. We observe an ultrafast Pauli blocking effect with leads to phonon hardening / blue-shifting.
Xia et al. Phys. Rev. B, 103:245205 (Jun 2021)
[
pdf ][ DOI:10.1103/PhysRevB.103.245205 ] We develop and apply the technique of time resolved cyclotron resonance to observe electron cooling in the narrow bandgap semiconductor indium antimonide and find excellent agreement with first principles GW calculations.
Xia et al. J. Phys. Chem. Lett., 12:3607-3617 (Apr 2021)
[
pdf ][ DOI:10.1021/acs.jpclett.1c00619 ] We measure THz photoconductivity of single crystals and thin films of the prototypical metal halide perovskite MAPbI3. This direct comparison combined with DFT calculations allows us to study the influence of grain boundaries on charge-carrier scattering, and hence mobility.