Polarization switching and relaxation dynamics of bismuth layered ferroelectric thin films: Role of oxygen defect sites and crystallinity

2011 ◽  
Vol 84 (9) ◽  
Author(s):  
Ji Hye Lee ◽  
Ran Hee Shin ◽  
William Jo
Keyword(s):  
Thin Films ◽  
Polarization Switching ◽  
Ferroelectric Thin Films ◽  
Oxygen Defect ◽  
Relaxation Dynamics ◽  
Defect Sites

THE ROLE OF OPTIMIZATION IN THE LANDAU THEORY OF FERROELECTRIC THIN FILMS

2009 ◽  
Author(s):  
J. F. Webb ◽  
Abdul Halim Hakim ◽  
Pandian Vasant ◽  
Nader Barsoum
Keyword(s):  
Thin Films ◽  
Landau Theory ◽  
Ferroelectric Thin Films

The enhanced piezoelectricity in compositionally graded ferroelectric thin films under electric field: A role of flexoelectric effect

2018 ◽  
Vol 123 (8) ◽  
pp. 084103 ◽  
Author(s):  
Ye Qiu ◽  
Huaping Wu ◽  
Jie Wang ◽  
Jia Lou ◽  
Zheng Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Electric Field ◽  
Ferroelectric Thin Films ◽  
Flexoelectric Effect

The role of nanoporosity on the local piezo and ferroelectric properties of lead titanate thin films

2015 ◽  
Vol 3 (5) ◽  
pp. 1035-1043 ◽  
Author(s):  
Alichandra Castro ◽  
Paula Ferreira ◽  
Brian J. Rodriguez ◽  
Paula M. Vilarinho
Keyword(s):  
Thin Films ◽  
Coercive Field ◽  
Lead Titanate ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Films ◽  
Piezoelectric Response ◽  
Nanoporous Films ◽  
Switching Behaviour ◽  
Dense Films

Nanoporous PbTiO3 films present enhanced tetragonality at lower temperatures than respective dense films. Moreover, the porosity present in the nanoporous films allows an increase of the local piezoelectric response and a decrease of the local coercive field. As a result, these nanoporous films might be used to improve the switching behaviour of ferroelectric thin films.

POLARIZATION SWITCHING IN FERROELECTRIC THIN FILMS STUDIED BY OPTICAL SECOND HARMONIC GENERATION

2007 ◽  
Vol 92 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Elena Mishina ◽  
Nataliya Sherstyuk ◽  
Yurii Golovko ◽  
Vladimir Muhortov ◽  
Alexandr Sigov
Keyword(s):  
Thin Films ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Polarization Switching ◽  
Ferroelectric Thin Films ◽  
Optical Second Harmonic Generation

Polarization Switching in CaBi4Ti4O15 Ferroelectric Thin Films

2004 ◽  
Vol 269 ◽  
pp. 41-44 ◽  
Author(s):  
De Sheng Fu ◽  
Kazuyuki Suzuki ◽  
Kazumi Kato
Keyword(s):  
Thin Films ◽  
Polarization Switching ◽  
Ferroelectric Thin Films

scholarly journals Orbital-Dependent Photodynamics of Strongly Correlated Clusters

2021 ◽  
Author(s):  
Jacob Garcia ◽  
Scott Sayres
Keyword(s):  
Theoretical Calculations ◽  
Advanced Materials ◽  
Strongly Correlated ◽  
Relaxation Dynamics ◽  
Pump Probe ◽  
Defect Sites ◽  
Atomic Precision ◽  
Bulk Scale ◽  
Probe Spectroscopy

Understanding the role of defect sites on the mechanism and lifetime of photoexcited state relaxation is critical for the ration-al design of advanced materials. Here, the ultrafast electronic relaxation dynamics of neutral nickel oxide clusters were inves-tigated with femtosecond pump-probe spectroscopy and supported with theoretical calculations to reveal that their excited state lifetimes are strongly dependent on the nature of the electronic transition. Absorption of a UV photon produces short lived (lifetime ~110 fs) dynamics in stoichiometric (NiO)n clusters (n < 6) that are attributed to a ligand to metal charge transfer (LMCT) and produces metallic-like electron-electron scattering. Oxygen vacancies introduce excitations with Ni-3d→Ni-4s and 3d→4p character, which increases the lifetimes of the sub-picosecond response by up to 80% and enables the formation of long-lived (lifetimes > 2.5 ps) states. The atomic precision and tunability of gas phase clusters are employed to highlight a unique reliance on the Ni orbital contributions to the photoexcited lifetimes, providing new insights to the anal-ogous band edge excitation dynamics of strongly correlated bulk-scale NiO materials.

scholarly journals Investigation of the Role of the Environment on the Photoluminescence and the Exciton Relaxation of CsPbBr3 Nanocrystals Thin Films

2020 ◽  
Vol 10 (6) ◽  
pp. 2148 ◽  
Author(s):  
Marco Anni ◽  
Arianna Cretì ◽  
Yuhai Zhang ◽  
Maria Luisa De Giorgi ◽  
Mauro Lomascolo
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Free Exciton ◽  
Intensity Increase ◽  
Optical Investigation ◽  
Relaxation Dynamics ◽  
Dynamic Effects ◽  
Radiative Relaxation ◽  
Pl Intensity

In this work, we present a detailed optical investigation of the effects of the environment on the photoluminescence (PL) spectra and the relaxation dynamics of pristine and aged CsPbBr3 nanocrystal (NC) thin films. We demonstrate that, contrary to previous results on similar NCs, the PL intensity of pristine NCs is higher when the sample is in wet air than in vacuum, due to the passivation of defects reducing the free exciton trapping and the bound excitons non-radiative relaxation. The aged NCs show a PL intensity increase in wet air nine times stronger than the pristine ones, due to an interplay between static and dynamic effects, increasing the number of emitting NCs and reducing the non-radiative recombination rate of free excitons. These results improve the understanding of the possible interactions between perovskite NCs and the environment, which could be relevant for the development of optical gas sensors exploiting perovskite NCs.

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