P. Amaladass

Study on photoluminescence from tris-(8-hydroxyquinoline)aluminum thin films and influence of light

Tris-(8-hydroxyquinoline)aluminum (Alq3), which is the most widely used material in organic electroluminescent devices, has been synthesized. Alq3 thin films have been deposited on glass and silicon substrates. The influence of light exposure on the optical properties of Alq3 thin films has been studied. It is confirmed that the photoluminescence (PL) of Alq3 thin film originates from its two geometrical isomers, namely, facial and meridional, which result from PL decay analysis (biexponential fit). It is also confirmed that the PL from both the isomers decreases for increasing light exposure time leading to the creation of luminescent quencher in Alq3 thin film.

Studies on the Fluorescence of Tris-(8-hydroxyquinoline)-Aluminum and the Effect of Light Exposure

Organic Tris-(8-hydroxyquinoline)aluminum (Alq3) thin films, one of the most widely used electron transport as well as emissive materials in the organic electroluminescent (EL) devices, have been deposited on glass substrates by thermal evaporation process. The deposited Alq3 thin films were exposed to light in the normal ambient. The effect of light exposure on the fluorescence of Alq3 sample and formation of luminescent quencher has been studied using cyclic voltammeter and 3D contour emission spectroscopy. It is observed that the luminescent quencher can be formed in the Alq3 during the light exposure, quenching the emission of light exposed sample. It is found that the energy of excitons in the Alq3 molecule in the light exposed Alq3 thin films can be non-radiatively transferred to its neighbouring luminescent quencher, quenching the emission of light exposed Alq3 thin films.