COLLOQUIUM: Electrodeposited Nanophotonics
CIC nanoGUNE Seminars
- Speaker
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Reginald M. Penner, Dept. of Chemistry, University of California, Irvine, USA.
- When
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2016/06/20
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
-
iCal
The phrase “nanophotonics†pertains to the manipulation, detection, and
emission of light to/from nanometer-scale devices. Lieber et al. described
the first light-emitting devices based upon semiconductor nanowires in 2001.
Since then, virtually all of the published work in this area has exploited
single crystalline nanomaterials.
In this presentation, we describe recent work from our laboratory in which
nanophotonic devices are prepared by the electrodeposition of polycrystalline
(pc), cadmium selenide (CdSe) in the form of nanowires and nanogap device
structures. The photodetectors and photon emitters we describe are symmetrical
metal-semiconductor-metal (M-S-M) devices prepared either by the evaporation
of two gold contacts onto linear arrays of pc-CdSe nanowires prepared using
lithographically patterned nanowires electrodeposition (LPNE), or by the
electrodeposition of pc-CdSe directly onto gold nanogaps. The properties of
these devices for detecting light using photoconductivity, and for generating
light by electroluminescence, are described.
These devices enable the detection of light by modulation of their
photoconductivity, and the generation of light by electroluminescence (EL).
For the detection of light, the intrinsic defectiveness of pc-CdSe is actually
an advantage, because it promotes rapid recombination of photoexcited carriers
and a prompt return to the dark conductivity state from the photoconductive
state of this material. A bandwidth of up to 175 kHz has been obtained for
lightemitting nanojunctions coupled with a photosensitivity of up to 500
metrics that are competitive with the current state-of-the-art. Surprisingly,
the defects associated with grain boundaries do not handicap pc-CdSe relative
to single crystalline CdSe for EL emission. We speculate that pc-CdSe works
reasonably well for EL because a channel for light emission, Poole-Frenkel
emission, is facilitated in pc-CdSe relative to single crystalline CdSe.
**Host** : J.M. Pitarke
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