Theoretical analysis of higher-order phonon sidebands in semiconductor luminescence spectra

A semiconductor luminescence formula is derived that includes phonon replica of arbitrary order based on a non-perturbative treatment of the electron-phonon interaction. The formula is used to analyze the extraordinarily strong sidebands observed with ZnO nanorods in recent experiments. Sidebands due to free and impurity-bound excitons are compared, and the generic differences between bulk and quantum-well emission are discussed.