Preparation of high quality ZnSe nanowires dominated by excitonic emission

A comprehensive model for the vapour liquid solid based growth of ZnSe nanowires is developed and applied to the optimisation of growth conditions for ZnSe nanowires. The model provided insight into the role of fluid dynamics and adatom incorporation, on the growth of nanowires. When applied experimentally, with appropriate conditions we show how high quality nanowires can be synthesized. In particular, such nanowires were shown to be dominated by excitonic emission with narrow linewidth attributed to free exciton and acceptor bound exciton emissions. The latter was shown to originate from VZn and related complexes, and as expected the emission is accompanied by strong LO phonon emission consistent with the high quality of the nanowires. This work can hence provide guidance for choice of growth conditions for exceptional quality ZnSe nanowires suitable for optoelectronic applications. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)