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Resumen: The performance of hybrid organic perovskite (HOP) for solar energy conversion is driving a renewed interest in their light emitting properties. The recent observation of broad visible emission in layered HOP highlights their potential as white-light emitters. Improvement of the efficiency of the material requires a better understanding of its photophysical properties. We present in-depth experimental investigations of white-light (WL) emission in thin films of the (C6H11NH3)2PbBr4. The broadband, strongly Stokes shifted emission presents a maximum at 90 K when excited at 3.815 eV, and below this temperature coexists with an excitonic edge emission. X-rays and calorimetry measurements exclude the existence of a phase transition as an origin of the thermal behavior of the WL luminescence. The free excitonic emission quenches at low temperature, despite a binding energy estimated to 280 meV. Time-resolved photoluminescence spectroscopy reveals the multicomponent nature of the broad emission. We analyzed the dependence of these components as a function of temperature and excitation energy. The results are consistent with the existence of self-trapped states. The quenching of the free exciton and the thermal evolution of the WL luminescence decay time are explained by the existence of an energy barrier against self-trapping, estimated to -10 meV.
Idioma: Inglés
DOI: 10.1021/acs.jpcc.5b06211
Año: 2015
Publicado en: Journal of Physical Chemistry C 119, 41 (2015), 23638-23647
ISSN: 1932-7447
Factor impacto JCR: 4.509 (2015)
Categ. JCR: CHEMISTRY, PHYSICAL rank: 30 / 144 = 0.208 (2015) - Q1 - T1
Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 39 / 271 = 0.144 (2015) - Q1 - T1
Categ. JCR: NANOSCIENCE & NANOTECHNOLOGY rank: 22 / 83 = 0.265 (2015) - Q2 - T1
Factor impacto SCIMAGO: 1.886 - Electronic, Optical and Magnetic Materials (Q1) - Energy (miscellaneous) (Q1) - Surfaces, Coatings and Films (Q1) - Physical and Theoretical Chemistry (Q1) - Nanoscience and Nanotechnology (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2013-44063-R
Tipo y forma: Artículo (PostPrint)
Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)

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