Excitons and phonons in GaN. Magnetooptical and spatially resolved investigations

摘要

A comprehensive study of the direct photoluminescence from free-exciton states in GaN using polarization-dependent and magnetooptical measure- ments is presented. We measured and identified fine-structure splittings in the n＝1 state of the A-exciton. From the magnetoluminescence data ob- tained in fields up to 15 T we determined the g-values of the conduction and valence bands parallel and perpendicular to the c-axis. Self-organized hexago- nal GaN pyramids of 5 μm width and covered by six{1101} side facets were investigated by spatially resolved cathodolummescence and micro-Raman spectroscopy.