Prof. Dr. Silvana Botti

Theory of excited states of integrated solid state systems
Ruhr-Universität Bochum

Contact

Hubs
  • Roadmap on Machine learning in electronic structure
    Kulik, H.J. and Hammerschmidt, T. and Schmidt, J. and Botti, S. and Marques, M.A.L. and Boley, M. and Scheffler, M. and Todorović, M. and Rinke, P. and Oses, C. and Smolyanyuk, A. and Curtarolo, S. and Tkatchenko, A. and Bartók, A.P. and Manzhos, S. and Ihara, M. and Carrington, T. and Behler, J. and Isayev, O. and Veit, M. and Grisafi, A. and Nigam, J. and Ceriotti, M. and Schütt, K.T. and Westermayr, J. and Gastegger, M. and Maurer, R.J. and Kalita, B. and Burke, K. and Nagai, R. and Akashi, R. and Sugino, O. and Hermann, J. and Noé, F. and Pilati, S. and Draxl, C. and Kuban, M. and Rigamonti, S. and Scheidgen, M. and Esters, M. and Hicks, D. and Toher, C. and Balachandran, P.V. and Tamblyn, I. and Whitelam, S. and Bellinger, C. and Ghiringhelli, L.M.
    Electronic Structure 4 (2022)
    view abstract10.1088/2516-1075/ac572f
  • Anisotropic layered Bi2 Te3 -In2 Te3 composites: Control of interface density for tuning of thermoelectric properties
    Liu, D. and Li, X. and De Castro Borlido, P.M. and Botti, S. and Schmechel, R. and Rettenmayr, M.
    Scientific Reports 7 (2017)
    Layered (Bi1-xInx) 2 Te3 -In2 Te3 (x = 0.075) composites of pronounced anisotropy in structure and thermoelectric properties were produced by zone melting and subsequent coherent precipitation of In2 Te3 from a (Bi1-xInx) 2 Te3 (x > 0.075) matrix. Employing solid state phase transformation, the Bi2 Te3 /In2 Te3 interface density was tuned by modifying the driving force for In2 Te3 precipitation. The structure-property relationship in this strongly anisotropic material is characterized thoroughly and systematically for the first time. Unexpectedly, with increasing Bi2 Te3 /In2 Te3 interface density, an increase in electrical conductivity and a decrease in the absolute Seebeck coefficient were found. This is likely to be due to electron accumulation layers at the Bi2 Te3 /In2 Te3 interfaces and the interplay of bipolar transport in Bi2 Te3. Significantly improved thermoelectric properties of Bi2 Te3 -In2 Te3 composites as compared to the single phase (Bi1-xInx) 2 Te3 solid solution are obtained. © The Author(s) 2017.
    view abstract10.1038/srep43611
  • Detection of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases in co-evaporated Cu2ZnSnSe4 thin-films
    Schwarz, T. and Marques, M.A.L. and Botti, S. and Mousel, M. and Redinger, A. and Siebentritt, S. and Cojocaru-Mirédin, O. and Raabe, D. and Choi, P.-P.
    Applied Physics Letters 107 (2015)
    Cu2ZnSnSe4 thin-films for photovoltaic applications are investigated using combined atom probe tomography and ab initio density functional theory. The atom probe studies reveal nano-sized grains of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 composition, which cannot be assigned to any known phase reported in the literature. Both phases are considered to be metastable, as density functional theory calculations yield positive energy differences with respect to the decomposition into Cu2ZnSnSe4 and ZnSe. Among the conceivable crystal structures for both phases, a distorted zinc-blende structure shows the lowest energy, which is a few tens of meV below the energy of a wurtzite structure. A band gap of 1.1 eV is calculated for both the Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases. Possible effects of these phases on solar cell performance are discussed. © 2015 AIP Publishing LLC.
    view abstract10.1063/1.4934847
  • Nano-scale characterization of thin-film solar cells
    Schwarz, T. and Cojocaru-Mirédin, O. and Choi, P.-P. and Lämmle, A. and Würz, R. and Mousel, M. and Redinger, A. and Siebentritt, S. and Botti, S. and Raabe, D.
    Microscopy and Microanalysis 20 (2014)
    view abstract10.1017/S1431927614003699

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