Recombination dynamics in wurtzite InP nanowires

Abstract

We report time-resolved photoluminescence investigations of as-grown wurtzite InP nanowires $({d}_{\text{av}}=16\text{ }\text{nm})$ on a (111) silicon substrate as a function of emission energy, temperature, and excitation fluence. The observed luminescence transients are well described by a biexponential decay process, with ${\ensuremath{\tau}}_{\mathrm{fast}}\ensuremath{\sim}0.3--0.7\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$ and ${\ensuremath{\tau}}_{\mathrm{slow}}\ensuremath{\sim}2--5\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$, which does not originate from band bending induced by surface states. The trends associated with the decay characteristics instead point to size-dependent localization effects in the narrow nanowires.