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 language | American English |
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Pages (from-to) | 13753-13763 |
Number of pages | 11 |
Journal | Journal of the American Chemical Society |
Volume | 140 |
Issue number | 42 |
DOIs | |
State | Published - 2018 |
Bibliographical note
Publisher Copyright:© 2018 American Chemical Society.
NREL Publication Number
- NREL/JA-5900-72021
Keywords
- PbSe QDs
- QD doping
- solar-photochemistry
- spectroscopy