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Surface State‐Induced Anomalous Negative Thermal Quenching of Multiferroic BiFeO 3 Nanowires (Phys. Status Solidi RRL 1/2018)
Author(s) -
Prashanthi Kovur,
Antić Željka,
Thakur Garima,
Dramićanin Miroslav D.,
Thundat Thomas
Publication year - 2018
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201870403
Subject(s) - materials science , nanowire , quenching (fluorescence) , semiconductor , multiferroics , condensed matter physics , surface states , nanotechnology , band gap , luminescence , optoelectronics , surface (topology) , fluorescence , ferroelectricity , optics , physics , dielectric , geometry , mathematics
The multiferroic wide‐bandgap semiconductor material BiFeO 3 (BFO) has attracted intense research interests due to its multifunctional properties and broad range of potential applications in optoelectronic devices. However, in onedimensional BFO nanostructures, because of the high surfaceto‐ volume ratio, surface states play a crucial role in their optical and electrical properties offering extraordinary functionalities. In their Letter (article no. 1700352 ), Kovur Prashanthi and coworkers report surface state induced anomalous negative thermal quenching of semiconductor BFO nanowires. The BFO nanowires show a rare phenomenon of negative thermal quenching (NTQ) of emission, where the emission intensity of certain peaks shows an increase as a function of temperature instead of the routinely observed decrease in luminescence intensity. A possible mechanism for the observed NTQ behaviour is proposed using electron trapping and de‐trapping at higher temperatures. The authors' studies reveal that the defect emission behaviour of the nanowires is due to the presence of localized surface states in the band gap caused by the oxygen vacancies. This phenomenon has neither been observed in thin‐film nor in bulk BiFeO 3 . Therefore, this effect is enhanced in the nanowires because of their high surface‐to‐volume ratio.