Origin of Broad Emission Spectra in InP Quantum Dots

Contributions from Structural and Electronic Disorder

Eric M. Janke, Nicholas E. Williams, Chunxing She, Danylo Zherebetskyy, Margaret H. Hudson, Lili Wang, David J. Gosztola, Richard D Schaller, Byeongdu Lee, Chengjun Sun, Gregory S. Engel, Dmitri V. Talapin

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The ensemble emission spectra of colloidal InP quantum dots are broader than achievable spectra of cadmium- and lead-based quantum dots, despite similar single-particle line widths and significant efforts invested in the improvement of synthetic protocols. We seek to explain the origin of persistently broad ensemble emission spectra of colloidal InP quantum dots by investigating the nature of the electronic states responsible for luminescence. We identify a correlation between red-shifted emission spectra and anomalous broadening of the excitation spectra of luminescent InP colloids, suggesting a trap-associated emission pathway in highly emissive core-shell quantum dots. Time-resolved pump-probe experiments find that electrons are largely untrapped on photoluminescence relevant time scales pointing to emission from recombination of localized holes with free electrons. Two-dimensional electronic spectroscopy on InP quantum dots reveals multiple emissive states and increased electron-phonon coupling associated with hole localization. These localized hole states near the valence band edge are hypothesized to arise from incomplete surface passivation and structural disorder associated with lattice defects. We confirm the presence and effect of lattice disorder by X-ray absorption spectroscopy and Raman scattering measurements. Participation of localized electronic states that are associated with various classes of lattice defects gives rise to phonon-coupled defect related emission. These findings explain the origins of the persistently broad emission spectra of colloidal InP quantum dots and suggest future strategies to narrow ensemble emission lines comparable to what is observed for cadmium-based materials.

Original languageEnglish
Pages (from-to)15791-15803
Number of pages13
JournalJournal of the American Chemical Society
Volume140
Issue number46
DOIs
Publication statusPublished - Nov 21 2018

Fingerprint

Quantum Dots
Semiconductor quantum dots
Phonons
Crystal defects
Electronic states
Electrons
Cadmium
X-Ray Absorption Spectroscopy
X ray absorption spectroscopy
Raman Spectrum Analysis
Colloids
Valence bands
Luminescence
Passivation
Linewidth
Genetic Recombination
Raman scattering
Spectrum Analysis
Photoluminescence
Lead

ASJC Scopus subject areas

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

Cite this

Janke, E. M., Williams, N. E., She, C., Zherebetskyy, D., Hudson, M. H., Wang, L., ... Talapin, D. V. (2018). Origin of Broad Emission Spectra in InP Quantum Dots: Contributions from Structural and Electronic Disorder. Journal of the American Chemical Society, 140(46), 15791-15803. https://doi.org/10.1021/jacs.8b08753

Origin of Broad Emission Spectra in InP Quantum Dots : Contributions from Structural and Electronic Disorder. / Janke, Eric M.; Williams, Nicholas E.; She, Chunxing; Zherebetskyy, Danylo; Hudson, Margaret H.; Wang, Lili; Gosztola, David J.; Schaller, Richard D; Lee, Byeongdu; Sun, Chengjun; Engel, Gregory S.; Talapin, Dmitri V.

In: Journal of the American Chemical Society, Vol. 140, No. 46, 21.11.2018, p. 15791-15803.

Research output: Contribution to journalArticle

Janke, EM, Williams, NE, She, C, Zherebetskyy, D, Hudson, MH, Wang, L, Gosztola, DJ, Schaller, RD, Lee, B, Sun, C, Engel, GS & Talapin, DV 2018, 'Origin of Broad Emission Spectra in InP Quantum Dots: Contributions from Structural and Electronic Disorder', Journal of the American Chemical Society, vol. 140, no. 46, pp. 15791-15803. https://doi.org/10.1021/jacs.8b08753
Janke, Eric M. ; Williams, Nicholas E. ; She, Chunxing ; Zherebetskyy, Danylo ; Hudson, Margaret H. ; Wang, Lili ; Gosztola, David J. ; Schaller, Richard D ; Lee, Byeongdu ; Sun, Chengjun ; Engel, Gregory S. ; Talapin, Dmitri V. / Origin of Broad Emission Spectra in InP Quantum Dots : Contributions from Structural and Electronic Disorder. In: Journal of the American Chemical Society. 2018 ; Vol. 140, No. 46. pp. 15791-15803.
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