Determination of effective mass of heavy hole from phonon-assisted excitonic luminescence spectra in ZnO

Longitudinal optical (LO) phonon-assisted luminescence spectra of free excitons in high-quality ZnO crystal were investigated both experimentally and theoretically. By using the rigorous Segall-Mahan model based on the Green's function, good agreement between the experimental emission spectra involving one or two LO phonons and theoretical spectra can be achieved when only one adjustable parameter (effective mass of heavy hole) was adopted. This leads to determination of the heavy-hole effective mass m(h perpendicular to) (0.8 m(0) and m(h parallel to) 5.0 m(0)) in ZnO. Influence of anisotropic effective masses of heavy holes on the phonon sidebands is also discussed. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3549724]