Temperature-Dependent Band Gap in Two-Dimensional Perovskites: Thermal Expansion Interaction and Electron-Phonon Interaction.
J Phys Chem Lett
; 10(10): 2546-2553, 2019 May 16.
Article
em En
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| ID: mdl-31050442
ABSTRACT
Two-dimensional organic-inorganic perovskites have attracted considerable interest recently. Here, we present a systematic study of the temperature-dependent photoluminescence on phase pure (n-BA)2(MA) n-1Pb nI3 n+1 ( n = 1-5) and (iso-BA)2(MA) n-1Pb nI3 n+1 ( n = 1-3) microplates obtained by mechanical exfoliation. The photoluminescence peak position gradually changes from a red-shift for n = 1 to a blue-shift for n = 5 with an increase in temperature in the (n-BA)2(MA) n-1Pb nI3 n+1 ( n = 1-5) series, while only a monotonous blue-shift has been observed for the (iso-BA)2(MA) n-1Pb nI3 n+1 ( n = 1-3) series, which can be attributed to the competition between the thermal expansion interaction and electron-phonon interaction. In the (n-BA)2(MA) n-1Pb nI3 n+1 ( n = 1-5) series, the thermal expansion interaction and electron-phonon interaction are both gradually enhanced and the former progressively dominates the latter from n = 1 to n = 5, resulting in the band gap versus temperature changing from a red-shift to a blue-shift. In contrast, both of these factors show a weaker layer thickness dependence, leading to the monotonous blue-shift in the (iso-BA)2(MA) n-1Pb nI3 n+1 ( n = 1-3) series.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
J Phys Chem Lett
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China