Stimulated emission at the second order stop-zone edge of the two-dimensional opal–zinc oxide photonic crystal

The fabrication of the 2D periodic structures in ZnO thin films by magnetron sputtering on the opal matrices was developed. The microstructures were characterized by AFM and SEM. The spontaneous and stimulated emissions of the ZnO layers on opal were studied at N2 laser excitation (λ = 337 nm). The stimulated emission near 397 nm was observed at room temperature from ZnO–opal structure. The threshold of the electron–hole plasma recombination laser process was ≅300 kW/cm2 for this structure. This threshold is two orders of magnitude smaller of that one for the flat ZnO–SiO2 films owing to DFB resonator effect in 2D structure.