Tuning Hot Carrier Cooling Dynamics by Dielectric Confinement in Two-Dimensional Hybrid Perovskite Crystals

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Jun Yin
  • Partha Maity
  • Rounak Naphade
  • Bin Cheng
  • Osman M. Bakr
  • Jean-Luc Brédas
  • Omar F. Mohammed

Detail(s)

Original languageEnglish
Pages (from-to)12621-12629
Journal / PublicationACS Nano
Volume13
Issue number11
Online published15 Oct 2019
Publication statusPublished - 26 Nov 2019
Externally publishedYes

Abstract

Hot carrier (HC) cooling is a critical photophysical process that significantly influences the optoelectronic performance of hybrid perovskite-based devices. The hot carrier extraction at the device interface is very challenging because of its ultrashort lifetime. Here, ultrafast transient reflectance spectroscopy measurements and time-domain ab initio calculations show how the dielectric constant of the organic spacers can control and slow the HC cooling dynamics in single-crystal 2D Ruddlesden-Popper hybrid perovskites. We find that  (EA)2PbI4 (EA  =  HOC2H4NH3+) that correspond to a high dielectric constant organic spacer has a longer HC cooling time compared to that of (AP)2PbI ( AP = HOC3H6NH3+) and (PEA)2PbI4 (PEA = C6H5C2H4NH3+). The slow HC relaxation process in the former case can be ascribed to a stronger screening of the Coulomb interactions, a small nonradiative internal conversion within the conduction bands, as well as a weak electron-phonon coupling. Our findings provide a strategy to prolong the hot carrier cooling time in low-dimensional hybrid perovskite materials by using organic spacers with reduced dielectric confinement. © 2019 American Chemical Society.

Research Area(s)

  • 2D hybrid perovskites, dielectric confinement, electron-phonon coupling, hot carrier cooling, nonadiabatic molecular dynamics

Citation Format(s)

Tuning Hot Carrier Cooling Dynamics by Dielectric Confinement in Two-Dimensional Hybrid Perovskite Crystals. / Yin, Jun; Maity, Partha; Naphade, Rounak; Cheng, Bin; He, Jr-Hau; Bakr, Osman M.; Brédas, Jean-Luc; Mohammed, Omar F.

In: ACS Nano, Vol. 13, No. 11, 26.11.2019, p. 12621-12629.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review