Ligand-Free, Quantum-Confined Cs2SnI6 Perovskite Nanocrystals

Dmitriy S. Dolzhnikov, Chen Wang, Yadong Xu, Mercouri G Kanatzidis, Emily A Weiss

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Tin-halide perovskite nanocrystals are a viable precursor for lead-free, high-efficiency active layers for photovoltaic cells. We describe a new synthetic procedure for quantum-confined Cs2SnI6 nanocrystals with size-dependent band gaps in the long-visible to near-infrared (1.38-1.47 eV). Hot injection synthesis produces particles with no organic capping ligands, with average diameters that increase from 12 ± 2.8 nm to 38 ± 4.1 nm with increasing reaction temperature. The band gap, energies of the first excitonic peak, ground-state bleach peak (in the transient absorption spectrum), and photoluminescence peak depend linearly on the inverse square of diameter, consistent with quantum-confined excitons with an effective mass of (0.12 ± 0.02)m0, where m0 is the mass of an electron, a factor of 4.6 smaller than that in the bulk material. Transient absorption measurements show that approximately 90% of the bleach amplitude decays within 30 ps, probably because of carrier trapping on unpassivated surface sites. The films made by simple drop-casting of Cs2SnI6 nanocrystal solutions, with no postsynthetic ligand exchange or removal, are smooth and uniform, resist delamination, and have no visible gaps at the film-substrate interface.

Original languageEnglish
Pages (from-to)7901-7907
Number of pages7
JournalChemistry of Materials
Volume29
Issue number18
DOIs
Publication statusPublished - Sep 26 2017

Fingerprint

Perovskite
Nanocrystals
Ligands
Energy gap
Tin
Photovoltaic cells
Delamination
Excitons
Ground state
Absorption spectra
Ion exchange
Photoluminescence
Casting
Lead
Infrared radiation
Electrons
Substrates
perovskite
Temperature
LDS 751

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Cite this

Ligand-Free, Quantum-Confined Cs2SnI6 Perovskite Nanocrystals. / Dolzhnikov, Dmitriy S.; Wang, Chen; Xu, Yadong; Kanatzidis, Mercouri G; Weiss, Emily A.

In: Chemistry of Materials, Vol. 29, No. 18, 26.09.2017, p. 7901-7907.

Research output: Contribution to journalArticle

Dolzhnikov, Dmitriy S. ; Wang, Chen ; Xu, Yadong ; Kanatzidis, Mercouri G ; Weiss, Emily A. / Ligand-Free, Quantum-Confined Cs2SnI6 Perovskite Nanocrystals. In: Chemistry of Materials. 2017 ; Vol. 29, No. 18. pp. 7901-7907.
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