COLLOQUIUM: Electrodeposited Nanophotonics

CIC nanoGUNE Seminars

Reginald M. Penner, Dept. of Chemistry, University of California, Irvine, USA.
nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
Add to calendar
Subscribe to Newsletter
COLLOQUIUM: Electrodeposited Nanophotonics 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 ** **