Some peculiarities of exciton luminescence of zinc oxide single crystals and powders

The new bands have been observed in the secondary emission spectrum of ZnO single crystals under near-resonance excitation. The energy position and the polarization behavior of these lines have been interpreted in terms of a resonant polariton–polariton scattering model. In the emission spectra of ZnO powders of different crystallite size, the manifestation of polariton–polariton interaction has not been detected. The quantum size effect was observed.