Crystal field splitting and spontaneous polarization in InP crystal phase quantum dots

Abstract

Crystal phase quantum dots are formed by vertically stacking zinc-blende and wurtzite phases during nanowire growth. In this work, we show, using an atomistic many-body approach, that crystal field splitting in the wurtzite phase, as well as spontaneous polarization originating from the phase interfaces, will strongly affect the properties of lowest hole states in InP crystal phase quantum dots, and in turn the excitonic optical spectra. We also show that the artifact-free modeling of crystal phase quantum dots should incorporate any additional potentials on equal footing with the electron-hole interaction. In this paper, we discuss a reliable theoretical framework that can be applied to investigate the electronic and optical properties of InP-based crystal phase quantum dots. The importance of accurate excitonic calculations for such systems is highlighted in view of their potential applications in nanowire photonics, yet further research is necessary for bringing theory and experiment in agreement.