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Colloidal nanoparticles gained interest because of their easy handling and the wide fields of application these materials. The classical synthesis of colloidal nanoparticles is the reduction of dissolved metal salts. In order to avoid side products and contaminations Laser ablation of metal targets in liquids represents a promising alternative synthesis route.[1] A drawback of this method is the relative low production rate. Suspensions of metal oxides can be used instead of bulk metal targets to overcome this problem. So far the efficient synthesis of copper and silver nanoparticles by laser ablation of CuO or Ag2O suspensions in organic solvents are known in literature.[2] We report the transfer of this method to other elements using suspensions of their oxides. The synthesized nanoparticles are characterized by UV-Vis spectroscopy, Atomic Force Microscopy and particular by Transmission Electron Microscopy. The focus of our interest lies on bismuth based semiconductors because of their high Seebeck coefficients (S) and their applicability in thermoelectric devices. The efficiency of a thermoelectric device at a certain Temperature (T) is defined by the figure of merit (zT): zT = (σ*S2*T)/κ The use of nanostructured materials can enhance the efficiency by reducing the thermal conductivity (κ) while the electrical conductivity (σ) stays nearly constant.[3] The investigation of the morphology and the chemical composition of the synthesized materials is essential to evaluate their capabilities for thermoelectric applications. Hence extensive Transmission Electron Microscopy studies are planned. [1] P.V. Kazakevich, A.V. Simakin, V.V. Voronov, G.A. Shafeev, Appl. Surf. Sci. 2006, 252, 4373- 4380. [2] a) M.-S. Yeh, Y.-S.Yang, Y.-P. Lee, H.-F. Lee, Y.-H. Yeh, C.-S. Yeh, J. Phys. Chem. B 1999, 103, 6851-6857; b) M. Kawasaki, N. Nishimura, J. Phys. Chem. C 2008, 112, 15647-15655; c) M. Kawasaki, J. Phys. Chem. C 2011, 115, 5165-5173. [3] M. Scheele, N. Oeschler, K Meier, A. Kornowski, C. Klinke, H. Weller, Adv. Funct. Mater. 2009, 19, 3476-3483. |
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