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Abstract Plasmonic hot‐electron‐assisted control of emission intensities and dynamics of CdSe/ZnS and infrared PbS quantum dots are studied. This is done by exploring the impact of Au/Si and Ag/Si Schottky junctions on the decay rates of such quantum dots when these junctions are placed in close vicinity of a Si/Al oxide charge barrier, forming metal‐oxide plasmonic metafilms. Such structures are used to investigate how metal‐dependent distributions of hot electrons and their capture via Schottky junctions can lead to suppression of the defect environments of quantum dots, offering a novel platform wherein off‐resonant (non‐Purcell) plasmonic processes are used to control exciton dynamics. These results show that Ag metafilms can enhance the emission of CdSe/ZnS quantum dots and elongate their lifetimes more than Au metafilms. This highlights the more efficient nature of Ag/Si Schottky junctions for hot electron excitation and capture. These results also show that such junctions can significantly suppress the nonradiative decay rates of PbS quantum dots at frequencies far from the plasmon resonances. These results demonstrate a field‐effect passivation of quantum dot defects via entrapment of hot electrons and control of emission intensities and dynamics of quantum dots via the nearly frequency‐independent electrostatic field of such electrons.
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Photons and charges from colloidal doped semiconductor quantum dots
The utility of colloidal semiconductor quantum dots as a source of photons and charge carriers for photonic and photovoltaic applications has created a large field of research focused on tailoring and broadening their functionality beyond what an exciton can provide. One approach towards expanding the range of characteristics of photons and charge carriers from quantum dots is through doping impurity ions ( e.g. Mn 2+ , Cu + , and Yb 3+ ) in the host quantum dots. In addition to the progress in synthesis enabling fine control of the structure of the doped quantum dots, a mechanistic understanding of the underlying processes correlated with the structure has been crucial in revealing the full potential of the doped quantum dots as the source of photons and charge carriers. In this review, we discuss the recent progress made in gaining microscopic understanding of the photophysical pathways that give rise to unique dopant-related luminescence and the generation of energetic hot electrons via exciton-to-hot electron upconversion.
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- Award ID(s):
- 1804412
- PAR ID:
- 10173586
- Date Published:
- Journal Name:
- Journal of Materials Chemistry C
- Volume:
- 7
- Issue:
- 47
- ISSN:
- 2050-7526
- Page Range / eLocation ID:
- 14788 to 14797
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/C9TC05150C
