Blue luminescent isolated Alq3 molecules in a solid-state matrix

Abstract

Thin vacuum deposited films of aluminum tris(8-hydroxyquinolinate) (Alq3) embedded in SiO2 matrix at concentrations corresponding to a single-molecule distribution are investigated. The spectral properties of the films are studied by luminescence spectroscopy. It is established that the dilution of Alq3 in the matrix leads to blueshift of the luminescence maximum up to 0.28eV compared to pure Alq3 layers. In contrast to the recently reported facial isomer of Alq3 in the crystalline δ phase, we conclude from our spectral data the observation of facial isomer molecules.