The effect of scattering particles on the photoluminescence of organic dye films

The strongly scattering and high gain in the active medium are necessary to produce the random laser. The random laser has been one of the focused research area in the laser scopes because of the random direction of the laser emission, small bulk, having no outside resonator, and potential applications in many fields. The PVK:Alq3:DCM organic films with TiO₂ scattering particles were manufactured by spin coating. The average radius of the TiO₂ particles is ~150 nm. The PL spectrum at the range of 400 nm to 750 nm was measured by the fluorescence spectrograph when the films were irradiated with a 390 nm pumping light. The PLE spectrum from 310 nm to 580 nm was measured by the fluorescence spectrograph at the 590 nm emission light. From the PL spectra of the organic film with the TiO₂ scattering particles and the pure organic film (without the TiO₂ scattering particles), it is showed that the fluorescence of the organic film increase when the TiO₂ scattering particles are introduced into the organic film. And PLE spectrum does also. From the above experiments, the random laser should be realized combing the PVK:Alq3:DCM organic films with the TiO₂ scattering particles in the coming research work.