Size and Temperature Dependence of Band-Edge Excitons in PbSe Nanowires

Abstract

We report the attenuance and temperature-dependent photoluminescence spectra of PbSe nanowires with diameters between 5.6 and 26.4 nm (12−23% relative standard deviation) and lengths greater than 1 μm. The nanowire first exciton energy varies between 0.3 and 0.6 eV as the diameter decreases from 26.4 to 5.6 nm, respectively. Compared to spherical PbSe nanocrystals, PbSe nanowires show less quantum confinement and larger Stokes shifts. The band gap temperature coefficient (d<i>E</i>_g/d<i>T</i>) decreases as the nanowire diameter decreases, consistent with previous results for PbSe spherical nanocrystals