Miri Kazes, David Y Lewis, Yuval Ebenstein, Taleb Mokari, and Uri Banin. 2002. “Lasing from semiconductor quantum rods in a cylindrical microcavity.” Advanced Materials, 14, 4, Pp. 317-321. Publisher's Version Abstract

Lasers based on colloidal semiconductor nanostructures can benefit from the remarkable spectral coverage afforded through the quantum confinement effect. The first observation of lasing for colloidal CdSe/ZnS quantum rods in solution using a cylindrical microcavity is reported here (see also inside front cover). Lasing in the same configuration was also observed for spherical nanocrystal quantum dots. For the quantum dots lasing is not polarized, but in quantum rods the laser emission is highly linearly polarized, a desirable feature for laser and photonic applications.

David Katz, Tommer Wizansky, Oded Millo, Eli Rothenberg, Taleb Mokari, and Uri Banin. 2002. “Size-dependent tunneling and optical spectroscopy of CdSe quantum rods.” Physical review letters, 89, 8, Pp. 086801. Publisher's Version Abstract


Photoluminescence excitation spectroscopy and scanning-tunneling spectroscopy are used to study the electronic states in CdSe quantum rods that manifest a transition from a zero-dimensional to a one-dimensional quantum-confined structure. Both optical and tunneling spectra show that the level structure depends primarily on the diameter of the rod and not its length. With increasing diameter, the band gap and the excited state level spacings shift to the red. The level structure was assigned using a multiband effective-mass model, showing a similar dependence on rod dimensions.

Andreas Eichhöfer, Assaf Aharoni, and Uri Banin. 2002. “Synthesis, structure, and optical properties of new cadmium chalcogenide clusters of the type [Cd10E4 (E'Ph) 12 (PR3) 4],(E, E'= Te, Se, S).” Zeitschrift für anorganische und allgemeine Chemie, 628, 11, Pp. 2415-2421. Publisher's Version Abstract

New cadmium chalcogenide cluster molecules [Cd10E4(E'Ph)12(Pn Pr3)4], E = Te, E' = Te () and [Cd10E4(E'Ph)12 (Pn Pr2Ph)4] E = Te, E' = Se (); E = Te E' = S (); E = Se, E' = S () have been synthesized and structurally characterized by single crystal X‐ray structure analysis. The influence of the variation of the chalcogen atom is investigated by structural means and by optical spectroscopy. All cluster‐molecules have a broad emission in the blue‐visible range at low temperature as indicated by photo luminescence (PL) measurements. A clear classification of the emission peak position can be made based on the E' species suggesting that the emission is assigned to transitions associated with the cluster surface ligands. Photoluminescence excitation and absorption measurements display a systematic shift of the band gap to the higher energies with the variation of E and E' from Te to Se to S, as also occurs in the respective series of the bulk semiconductors.

Nir Tessler, Vlad Medvedev, Miri Kazes, ShiHai Kan, and Uri Banin. 2002. “Efficient near-infrared polymer nanocrystal light-emitting diodes.” Science, 295, 5559, Pp. 1506-1508. Publisher's Version Abstract

Conjugated polymers and indium arsenide–based nanocrystals were used to create near-infrared plastic light-emitting diodes. Emission was tunable from 1 to 1.3 micrometers—a range that effectively covers the short-wavelength telecommunications band—by means of the quantum confinement effects in the nanocrystals. The external efficiency value (photons out divided by electrons in) is ∼0.5% (that is, >1% internal) and is mainly limited by device architecture. The near-infrared emission did not overlap the charge-induced absorption bands of the polymer.