n-Type PbSe Quantum Dots via Post-Synthetic Indium Doping

Matthew Beard, Haipeng Lu, Gerard Carroll, Xihan Chen, Nathan Neale, Elisa Link, Peter Sercel, Dinesh Amarasinghe, Federico Rabuffetti, Alexander Efros

Research output: Contribution to journalArticlepeer-review

28 Scopus Citations

Abstract

We developed a postsynthetic treatment to produce impurity n-type doped PbSe QDs with In3+ as the substitutional dopant. Increasing the incorporated In content is accompanied by a gradual bleaching of the interband first-exciton transition and concurrently the appearance of a size-dependent, intraband absorption, suggesting the controlled introduction of delocalized electrons into the QD band edge states under equilibrium conditions. We compare the optical properties of our In-doped PbSe QDs to cobaltocene treated QDs, where the n-type dopant arises from remote reduction of the PbSe QDs and observe similar behavior. Spectroelectrochemical measurements also demonstrate characteristic n-type signatures, including both an induced absorption within the electrochemical bandgap and a shift of the Fermi-level toward the conduction band. Finally, we demonstrate that the In3+ dopants can be reversibly removed from the PbSe QDs, whereupon the first exciton bleach is recovered. Our results demonstrate that PbSe QDs can be controllably n-type doped via impurity aliovalent substitutional doping.

Original languageAmerican English
Pages (from-to)13753-13763
Number of pages11
JournalJournal of the American Chemical Society
Volume140
Issue number42
DOIs
StatePublished - 2018

Bibliographical note

Publisher Copyright:
© 2018 American Chemical Society.

NREL Publication Number

  • NREL/JA-5900-72021

Keywords

  • PbSe QDs
  • QD doping
  • solar-photochemistry
  • spectroscopy

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