Electrical Detection of Quantum Dot Hot Electrons Generated via a Mn 2+ -Enhanced Auger Process
An all-solid-state quantum-dot-based photon-to-current conversion device is demonstrated that selectively detects the generation of hot electrons. Photoexcitation of Mn -doped CdS quantum dots embedded in the device is followed by efficient picosecond energy transfer to Mn with a long-lived (millise...
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Veröffentlicht in: | The journal of physical chemistry letters 2017-01, Vol.8 (1), p.126-130 |
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Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
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Zusammenfassung: | An all-solid-state quantum-dot-based photon-to-current conversion device is demonstrated that selectively detects the generation of hot electrons. Photoexcitation of Mn
-doped CdS quantum dots embedded in the device is followed by efficient picosecond energy transfer to Mn
with a long-lived (millisecond) excited-state lifetime. Electrons injected into the QDs under applied bias then capture this energy via Auger de-excitation, generating hot electrons that possess sufficient energy to escape over a ZnS blocking layer, thereby producing current. This electrically detected hot-electron generation is correlated with a quench in the steady-state Mn
luminescence and the introduction of a new nonradiative excited-state decay process, consistent with electron-dopant Auger cross-relaxation. The device's efficiency at detecting hot-electron generation provides a model platform for the study of hot-electron ionization relevant to the development of novel photodetectors and alternative energy-conversion devices. |
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ISSN: | 1948-7185 1948-7185 |
DOI: | 10.1021/acs.jpclett.6b02219 |