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HL: Fachverband Halbleiterphysik
HL 42: Oxide semiconductors
HL 42.1: Vortrag
Mittwoch, 18. März 2020, 09:30–09:45, POT 51
Modelling native defects in transparent conducting oxides using the hybrid QM/MM embedded cluster technique — •Qing Hou, John Buckeridge, Alexey A. Sokol, Jingcheng Guan, and C. Richard A. Catlow — Kathleen Lonsdale Materials Chemistry, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
For n-type transparent conducting oxide (TCO) materials such as SnO2, In2O3 and ZnO, native defects play a key role in electronic conductivity. Depending on their electronic structure, energetics and geometries, defects can act as donors, resulting in intrinsic n-type conductivity, or can compensate extrinsic donors such as Sn in In2O3. Predictive modelling of the properties of defects in such systems requires a detailed description of the dielectric response of the host material, which can be difficult to obtain using standard supercell techniques. Here, we employ the hybrid quantum mechanical/molecular mechanical (QM/MM) embedded cluster method, a multi-region approach that allows us to model defects at the true dilute limit, with polarisation effects described in an accurate and consistent manner. Moreover, we develop techniques to analyse the energetic balance between electrons bound to donors in diffuse and compact states, a difficult problem regardless of the model employed. We benchmark our results where possible and find good agreement with experiments for a variety of defect-related properties.