Metal-semiconductor hybrid nanoparticles: Halogen induced shape control

Metal-semiconductor hybrid nanoparticles combine materials with different physical properties in one nanostructure. Charge separation processes and potentially increased conductivity in thin film devices make them promising candidates for advanced applications in photocatalysis or (opto) electronics. The work on hand deals with the preparation of CdSe nanoparticles that later act as seeds for the defined deposition of metals and with the electrical characterisation of monolayers of the resulting hybrid structures. In context with the shape control of the semiconductor component in a hot injection synthesis, the role of halogen compounds and the influence of their molecular structure are examined. Analytically as well as theoretically supported explanations for the formation of the evolving hexagonal pyramidal shape, which is especially favourable for metal deposition, are presented. The deposition of different metals onto the obtained semiconductor components is examined and unusual instabilities of an Au shell on CdSe hybrid nanoparticles are investigated. Furthermore, the impact of deposited Pt on the electrical transport of CdSe nanopyramids is demonstrated.