Boosting Transport Distances for Molecular Excitons within Photoexcited Metal-Organic Framework Films

Subhadip Goswami, Michelle Chen, Michael R. Wasielewski, Omar K. Farha, Joseph T. Hupp

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Herein, we describe the fabrication of porphyrin-containing metal-organic framework thin films with 1,4-diazabicyclo[2.2.2]octane (DABCO) pillaring linkers and investigate exciton transport within the films. Steady-state emission spectroscopy indicates that the exciton can traverse up to 26 porphyrin layers when DABCO is used as a pillaring linker, whereas on average only 9-11 layers can be traversed when either 4,4'-bipyridine (a pillaring linker) or pyridine (a nonpillaring, layer-interdigitating ligand) is used. These results can be understood by taking into account the decreased separation distances between transition dipoles associated with chromophores (porphyrins) sited in adjacent layers. Shorter distances translate into faster Förster-type exciton hopping and, therefore, more hops within the few nanosecond lifetime of the porphyrin's singlet excited-state. The findings have favorable implications for the development of MOF-based photoelectrodes and photoelectrochemical energy-conversion devices.

Original languageEnglish
Pages (from-to)34409-34417
Number of pages9
JournalACS Applied Materials and Interfaces
Volume10
Issue number40
DOIs
Publication statusPublished - Oct 10 2018

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Keywords

  • energy transfer
  • exciton hopping
  • layer-by-layer
  • metal-organic framework
  • transition dipole

ASJC Scopus subject areas

  • Materials Science(all)

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