Abstract
Persistent spectral hole-burning is a widely used technique in high-resolution spectroscopy to uncover interactions between organic dye molecules and a solid host. Recently, there has been growing interest in understanding the relation between the structure of dye-host systems and hole-burning at higher temperatures. It has been claimed that one reason for hole formation up to temperatures of about 80 K in some freebase porphine-doped polymeric systems is the suppression of the structural relaxation in the polymer due to the existence of hydrogen-bonding in the matrix1-3). In a different approach we report on dye-surface systems showing high-temperature hole-burning properties. In dye-surface systems organic dye molecules are adsorbed on the heterogeneous surface of γ-alumina (γ-Al2O3) powder to reduce the electron-phonon coupling between dye and host.