Luminescent properties of organic–inorganic hybrid films fabricated by capillary coating technique

Organo-inorganic luminescent hybrid films were obtained by two different versions of the capillary coating technique. The first one included preliminary synthesis of hybrid material powder based on CaF 2 inorganic matrix and 8-hydroxyquinoline lithium as an organic constituent, preparation of a suspension based on hybrid material powder and an organic solvent and subsequent fabrication of a hybrid film. The second variant consisted in the in situ synthesis of hybrid materials directly in capillary-coated films by heat treatment or microwave treatment of the dried films. The films were obtained using boric acid as an inorganic precursor and 8-hydroxyquinoline lithium, tris(8-hydroxyquinoline) aluminum(III) or pure 8-hydroxyquinolinol as organic precursors for hybrid material synthesis. Films were deposited on surfaces with different roughness (RMS from 20 nm to 10 μm). The photoluminescence spectra and luminescence decay kinetics of hybrid films were measured. All obtained films exhibited intense broadband luminescence with a maximum at 480–520 nm.