Photoluminescence properties of bare and ZnO infilled artificial opal

Photoluminescence of bare and ZnO infilled artificial opals was investigated. A presence of a photonic band gap results in distortion of the photoluminescence spectra of both the bare and ZnO infilled opal nanocomposite. Filling of the opal with ZnO resulted in a shift of the Bragg diffraction peak from 430 to 460 nm. The emission from ZnO infilled opal contains no UV photoluminescence from ZnO nanocrystals, while the ZnO nanocrystals deposited on substrate by the same method exhibit strong excitonic UV emission. Although a high temperature treatment in ambient air results in an increase in the photoluminescence intensity of the ZnO nanocrystals, the quenched behavior of the excitonic emission from ZnO nanocrystals embedded in the opal matrix remains. A domination of the artificial opal matrix intrinsic emission in the photoluminescence spectra from the untreated as well as heat treated ZnO filled opal nanocomposites is observed.