Colloidal semiconductor-plasmonic copper sulfide nanocrystals

3^rd International Conference and Exhibition on Materials Science & Engineering

October 06-08, 2014 Hilton San Antonio Airport, USA

P Davide Cozzoli

Accepted Abstracts: Material Sci Eng

Abstract :

Colloidal nanocrystals with heavily doped structure represent an interesting class of dual-functional nanomaterials, in which the distinctive optoelectronic properties of low-dimensional semiconductors and localized surface plasmon resonance (LSPR) response, typical of noble metals, are combined. The plasmonic behavior originates from excess free carriers associated with cation/anion vacancies or ionized dopant atoms in the lattice, leading to intense extinction bands at near-infrared (NIR) wavelengths. In this talk, the author will discuss a surfactant-assisted nonaqueous synthesis of anisotropic-shaped copper sulfide (Cu2-xX) nanocrystals, trapped in selected crystal structures, which exhibit intense, size-tunable LSPR at NIR frequencies. The composition and geometry dependence of LSPR features are interpreted on the basis of theoretical calculations performed by the Discrete Dipole Approximation (DDA) method. Particular emphasis is put on the assessment and interpretation of optical properties of nanocrystals in the metallic-like covellite structure (CuS), which can support LSPR response due to a significant density of lattice-constitutional valence-band free holes in their stoichiometric (undoped) lattice. As a consequence of the unique electronic properties of the CuS nanocrystals and of their monodispersity, coherent excitation of symmetric radial breathing modes has been detected for the first time in transient absorption experiments at LSPR wavelengths.

Biography :

P Davide Cozzoli received his PhD Award in Chemical Sciences in 2004 from the University of Bari, Italy. Since 2007, he is Senior Staff Researcher at the University of Salento, Lecce, Italy. Currently, he leads the Nanochemistry Division of the National Nanotechnology laboratory of CNR Nanoscience Institute, Lecce, Italy, and serves as Associate Editor of Science of Advanced Materials, Journal of Nanoengineering and Nanomanufacturing, Materials Focus, and Journal of Crystallography. His research interests involve development of advanced inorganic nanoparticles for applications in catalysis, photovoltaics, energy storage, and biomedicine. So far, he has published about 105 papers (H-index=31).