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Tailoring new properties in oxide films through doping

Giovedi 1 febbraio 2018, ore 15.00, aula Seminari, S3 Cnr Nano, terzo piano, edificio Fisica, Dipartimento FIM, Modena

Relatore: Stefania Benedetti

Abstract: Doping has shown to be a versatile means to tune the properties of oxide materials for electronic, optical and chemical applications.[1,2] Dopants modify bonds in the host lattice and can introduce new states in the band gap, giving rise to new optical transitions and modifying the conductance behavior of the material. For this reason the insertion of aliovalent dopant atoms and the interplay between defects and dopants can be used to tune the physical properties of the host oxide. I present here our study of doped oxides (Al:ZnO, MgO) with high resolution and atomic control.[3,4] Our investigation clarifies by means of electron spectroscopies and comparison with DFT calculations the modification of the electronic and structural properties occurring in the systems. The combination of X-ray spectroscopic investigation with their theoretical interpretation allowed us to identify the single chemical and structural contributions that give origin to the final properties of the samples, to explain the mechanisms leading to spontaneous diffusion and how the oxide reaches charge equilibrium following different pathways for different dopant species. The comprehension of these mechanisms at an atomic level is the basis to tailor the material functionality.

[1] E. W. McFarland et al., Chem. Rev. 113, 4391 (2013)
[2] P. D. C. King and T. D. Veal, J. Phys.: Condens. Matter, 2011, 23, 334214.
[3] S. Benedetti et al., J. Phys. Chem. C 120, 13604 (2016)
[4] S. Benedetti, A. Calzolari et al., Phys. Chem. Chem. Phys. 19, 29364 (2017)

[Ultimo aggiornamento: 29/01/2018 12:10:53]