Electrical Detection of Quantum Dot Hot Electrons Generated via a Mn 2+ -Enhanced Auger Process.

Autor:	Barrows CJ; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., Rinehart JD; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., Nagaoka H; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., deQuilettes DW; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., Salvador M; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., Chen JI; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., Ginger DS; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States., Gamelin DR; Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
Jazyk:	angličtina
Zdroj:	The journal of physical chemistry letters [J Phys Chem Lett] 2017 Jan 05; Vol. 8 (1), pp. 126-130. Date of Electronic Publication: 2016 Dec 14.
DOI:	10.1021/acs.jpclett.6b02219
Abstrakt:	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 2+ -doped CdS quantum dots embedded in the device is followed by efficient picosecond energy transfer to Mn 2+ 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 2+ 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.
Databáze:	MEDLINE
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