Highly Luminescent Silicon Nanocrystals with Discrete Optical Transitions

• DOI: 10.1021/ja002956f
• Publication Date: 2002-07-26T04:56:38Z
• Authors: Justin D. Holmes; Kirk J. Ziegler; R. Christopher Doty; Lindsay E. Pell; Keith P. Johnston; Brian A. Korgel
• Keywords: Stokes shift

A new synthetic method was developed to produce robust, highly crystalline, organic-monolayer passivated silicon (Si) nanocrystals in a supercritical fluid. By thermally degrading the Si precursor, diphenylsilane, presence of octanol at 500 degrees C and 345 bar, relatively size-monodisperse sterically stabilized ranging from 15 40 diameter could be obtained significant quantities. Octanol binds nanocrystal surface through an alkoxide linkage provides steric stabilization hydrocarbon chain. The absorbance photoluminescence excitation (PLE) spectra exhibit blue shift optical properties bulk band gap energy 1.2 eV due quantum confinement effects. stable clusters show efficient (15 A) or green (25-40 band-edge photoemission with luminescence yields up 23% room temperature, electronic structure characteristic predominantly indirect transition, despite extremely small particle size. smallest nanocrystals, diameter, discrete transitions, effects for crystalline narrow size distribution.