Recombination dynamics in wurtzite InP nanowires

We report time-resolved photoluminescence investigations of as-grown wurtzite InP nanowires (d(av)=16 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 tau(fast)similar to 0.3-0.7 ns and tau(slow)similar to 2-5 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.