Polarization spectra of excitonic luminescence of bare ZnCdSe/ZnSe quantum wires

Abstract

Linearly polarized luminescence spectra of bare (unburied) semiconductor structures with ZnCdSe/ZnSe quantum wires, obtained by reactive ion etching, were investigated. It was found that, regardless of the orientation of the linear polarization of the exciting light, the luminescence radiation of the quantum wires is polarized parallel to the axis of the wires, while the radiation of the buffer layer of the isotropic ZnSe barrier material is oriented perpendicular to the axis of the wires. The polarization features found are due to the modification of the modes of the electromagnetic field near open quantum wires, which occurs as a result of the presence of the vertical interfaces between media with strongly different permittivities. It was also found that, when linearly polarized excitation is used, the alignment of exciton dipole moments strongly influences the polarization properties of the luminescence.