Počet záznamů: 1  

Concurrent bandgap narrowing and polarization enhancement in epitaxial ferroelectric nanofilms

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    0448711 - FZÚ 2016 RIV NL eng J - Článek v odborném periodiku
    Tyunina, Marina - Yao, L. - Chvostová, Dagmar - Dejneka, Alexandr - Kocourek, Tomáš - Jelínek, Miroslav - Trepakov, Vladimír - van Dijken, S.
    Concurrent bandgap narrowing and polarization enhancement in epitaxial ferroelectric nanofilms.
    Science and Technology of Advanced Materials. Roč. 16, č. 2 (2015), 026002. ISSN 1468-6996. E-ISSN 1878-5514
    Grant CEP: GA ČR GAP108/12/1941
    Institucionální podpora: RVO:68378271
    Klíčová slova: epitaxial growth * ferroelectric nanofilms
    Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
    Impakt faktor: 3.433, rok: 2015

    Perovskite-type ferroelectric (FE) crystals are wide bandgap materials with technologically valuable optical and photoelectric properties. Here, versatile engineering of electronic transitions is demonstrated in FE nanofilms of KTaO3, KNbO3 (KNO), and NaNbO3 (NNO) with a thickness of 10–30 unit cells. Control of the bandgap is achieved using heteroepitaxial growth of new structural phases on SrTiO3 (001) substrates. Compared to bulk crystals, anomalous bandgap narrowing is obtained in the FE state of KNO and NNO films. This effect opposes polarization-induced bandgap widening, which is typically found for FE materials. Transmission electron microscopy and spectroscopic ellipsometry measurements indicate that the formation of higher-symmetry structural phases of KNO and NNO produces the desirable red shift of the absorption spectrum towards visible light, while simultaneously stabilizing robust FE order.
    Trvalý link: http://hdl.handle.net/11104/0250352

     
     
Počet záznamů: 1  

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