'Similarity law' in the phonon spectrum of bound exciton luminescence in GaP:N

Abstract
A low temperature spectrum with periodically repeated phonon structures, induced by the localised vibration model in nitrogen doped GaP has been observed. Experiments and analysis show that all of the phonon sidebands from nitrogen-bound exciton luminescence come from multi-phonon optical transition processes described by Huang-Rhys' theory.