Optical Fabrication of Semiconductor Single-Crystalline Microspheres in Superfluid Helium

Abstract

ABSTRACTWe successfully fabricated semiconductor microspheres of ZnO, ZnSe, etc., by laser ablation in superfluid helium and investigated their morphology and optical properties. Time-resolved photoluminescence spectroscopy in ultraviolet region of single ZnO microspheres shows luminescence spectra with mode structures and remarkable reduction of the luminescence decay time compared to that of polycrystals or non-spherical microparticles. This indicates strong light-matter interaction due to efficient light-confinement in the ZnO microspheres. In addition, the fabricated ZnSe microspheres also show the photoluminescence spectra with typical mode structures indicating their high sphericity.