Photoluminescence and Third Harmonic Generation in ZnPc Thin Films
Michal Wojdyla, Wacla Bala, Beata Derkowska, Zbigniew Lukasiak, Robert Czaplicki, Zouhair Sofiani, Sylvie Dabos-Seignon and Bouchta Sahraoui
The thin films of zinc phthalocyanine (ZnPc) were investigated using photoluminescence (PL), UV-ViS and FT-IR absorption and Raman spectroscopy. The nonlinear optical properties of these materials were investigated by the third harmonic generation (THG) and degenerate four wave mixing (DFWM). The PL spectra were measured in the spectral range 350 nm –1150 nm and at the temperature range from 13 K to 320 K. The PL spectra consist of three main bands positioned at 1.14 eV, 1.84 eV and 2.51 eV and have been distributed on the Gaussian line shape. The temperature dependence of photoluminescence spectra were explained by means of structural transformation caused by changes of bond lengths and angles of ZnPc molecules. The FT-IR measurements have been performed in the temperature range 77 K –523 K. The changes of the band position, intensity and full width at half maximum (FWHM) of selected FT-IR and Raman modes while heating and cooling processes have been determined.