STARK-EFFECT MEASUREMENTS ON SINGLE PERYLENE MOLECULES

Fluorescence excitation spectra of single perylene molecules embedded in the Shpol'skii matrix n-nonane have been investigated at 1.7 K. On a time scale which is considerably larger than the tripler lifetime of the molecule, discrete spectral jumps of the single molecular absorpt ion lines are observed. To investigate this jump behaviour, fluorescen ce excitation spectra at different applied electric field strengths to the sample have been recorded. From the resulting Stark shifts and th e spectral jumps a maximum distance between the molecules and disturbi ng two-level systems can be estimated.