Optical studies of phthalocyanine molecules in PMMA matrix

Abstract

Optical absorption and emission spectral studies of various rare earth phthalocyanine (RePc) molecules in polymethyl methacrylate (PMMA) matrix have been reported for the first time. The recorded spectra are analyzed to yield the important spectral parameters such as optical absorption cross-section ( σ a), emission cross-section ( σ e), oscillator strength ( f), dipole strength ( q), fluorescence band width (Δ λ), emission wavelength ( λ), radiative decay time ( τ) and optical gain ( G). Analysis shows that the emission cross-section and optical gain are maximum in the europium diphthalocyanine (EuH(Pc) 2)-doped PMMA matrix. A comparison of the calculated emission parameters with other polymer matrices viz. PVA and cyano acrylate, shows that they are smaller in the neodymium diphthalocyanine (NdH(Pc) 2) and samarium diphthalocyanine (SmH(Pc) 2)-impregnated PMMA matrices. The parameters are found to be improved in the PMMA matrices of lanthanum phthalocyanine (LaPc) and EuH(Pc) 2 as compared to the PVA matrix. On the other hand, these parameters greatly underestimate the values for all the PMMA-based systems as compared to the borate glassy systems.