Carrier Diffusion Lengths of over 500 nm in Lead-Free Perovskite CH3NH3SnI3 Films

Lin Ma, Feng Hao, Constantinos C. Stoumpos, Brian T. Phelan, Michael R Wasielewski, Mercouri G Kanatzidis

Research output: Contribution to journalArticle

78 Citations (Scopus)

Abstract

The dynamics of photoexcited lead-free perovskite films, CH3NH3SnI3, were studied using broadband transient absorption and time-resolved fluorescence spectroscopy. Similar to its lead analogue CH3NH3PbI3, we show that free carrier (electrons and holes) recombination is also the dominant relaxation pathway in CH3NH3SnI3 films. The slow hot carrier relaxation time is 0.5 ps. Long carrier diffusion lengths for electrons (279 ± 88 nm) and holes (193 ± 46 nm) were obtained from fluorescence quenching measurements. We also show that SnF2 doping in the CH3NH3SnI3 film effectively increases the fluorescence lifetime up to 10 times and gives diffusion lengths exceeding 500 nm. These results suggest that the photophysics of CH3NH3SnI3 perovskite are as favorable as those of CH3NH3PbI3, demonstrating that it is a promising nontoxic lead-free replacement for lead iodide perovskite-based solar cells.

Original languageEnglish
Pages (from-to)14750-14755
Number of pages6
JournalJournal of the American Chemical Society
Volume138
Issue number44
DOIs
Publication statusPublished - Nov 9 2016

    Fingerprint

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this