Berlin 2015 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 13: Focus Session (with TT): Functional semiconductor nanowires II
HL 13.11: Talk
Monday, March 16, 2015, 18:15–18:30, EW 201
Monitoring cation exchange from CdSe to Ag2Se in individual nanowires. — •Cornelius Fendler1, August Dorn1, Hauke Heller2, Andreas Kornowski2, Robert Schön2, and Robert Blick1 — 1Center for Hybrid Nanostructures, Institutes of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11c, 20355 Hamburg, Germany — 22Institut for physical chemistry, Grindelallee 117, 20146 Hamburg
Cation exchange is a relatively simple tool to broaden the range of material compositions available in nanostructures.[1] With sufficient monitoring tools, partial cation exchange can be used to tune the material properties to desired values.[2]
In this study we investigated the correlation between the electrical conductivity and the degree of the exchange from CdSe to Ag2Se on individuelal nanowires. We used the solution-liquid-solid (SLS) process to directly grow CdSe nanowires off bismuth thin films on Si/SiO2-substrates. Single CdSe wires with diameters of 30 nm to 100 nm and lengths exceeding 10 µm were contacted with titanium electrodes by confocal laser lithography. The conductivity of the individual nanowires was monitored in situ during the cation exchange reaction from CdSe to Ag2Se. At different stages of the cation exchange reaction the samples were removed from solution, the voltage-current-characteristics were measured and the material composition was determined by wavelength-dispersive X-ray spectroscopy (WDS).
[1] J.B. Rivest et al., Chem. Soc. Rev.,2013, 42, 89.
[2] A. Dorn et al., Nano Lett. 2010, 10, 3948-3951.