title: Dimensional crossover in semiconductor nanostructures.
abstract: Recent advances in semiconductor nanostructure syntheses provide unprecedented control over electronic quantum confinement and have led to extensive investigations of their size- and shape-dependent optical/electrical properties. Notably, spectroscopic measurements show that optical bandgaps of one-dimensional CdSe nanowires are substantially (approximately 100 meV) lower than their zero-dimensional counterparts for equivalent diameters spanning 5-10 nm. But what, exactly, dictates the dimensional crossover of a semiconductor's electronic structure? Here we probe the one-dimensional to zero-dimensional transition of CdSe using single nanowire/nanorod absorption spectroscopy. We find that carrier electrostatic interactions play a fundamental role in establishing dimensional crossover. Moreover, the critical length at which this transition occurs is governed by the aspect ratio-dependent interplay between carrier confinement and dielectric contrast/confinement energies.
authors: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors: Matthew P
authors: MP
authors: McDonald
authors: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors: Rusha
authors: R
authors: Chatterjee
authors: Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors: Jixin
authors: J
authors: Si
authors: Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors: Boldizsár
authors: B
authors: Jankó
authors: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors: Masaru
authors: M
authors: Kuno