Enhanced Near-Infrared-to-Visible Upconversion by Synthetic Control of PbS Nanocrystal Triplet Photosensitizers

Zhiyuan Huang, Zihao Xu, Melika Mahboub, Zhiming Liang, Paulina Jaimes, Pan Xia, Kenneth R. Graham, Ming L. Tang, Tianquan Lian

Research output: Contribution to journalArticlepeer-review

58 Scopus citations

Abstract

Photon upconversion employing semiconductor nanocrystals (NCs) makes use of their large and tunable absorption to harvest light in the near-infrared (NIR) wavelengths as well as their small gap between singlet and triplet excited states to reduce energy losses. Here, we report the highest QY (11.8%) thus far for the conversion of NIR to yellow photons by improving the quality of the PbS NC. This high QY was achieved by using highly purified lead and thiourea precursors. This QY is 2.6 times higher than from NCs prepared with commercially available lead and sulfide precursors. Transient absorption spectroscopy reveals two reasons for the enhanced QY: longer intrinsic exciton lifetimes of PbS NCs and the ability to support a longer triplet lifetime for the surface-bound transmitter molecule. Overall, this results in a higher efficiency of triplet exciton transfer from the PbS NC light absorber to the emitter and thus a higher photon upconversion QY.

Original languageEnglish
Pages (from-to)9769-9772
Number of pages4
JournalJournal of the American Chemical Society
Volume141
Issue number25
DOIs
StatePublished - Jun 26 2019

Bibliographical note

Publisher Copyright:
Copyright © 2019 American Chemical Society.

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint

Dive into the research topics of 'Enhanced Near-Infrared-to-Visible Upconversion by Synthetic Control of PbS Nanocrystal Triplet Photosensitizers'. Together they form a unique fingerprint.

Cite this