FLUORESCENCE PROPERTIES OF SUBMONOLAYERS OF RHODAMINE 6G IN FRONT OF A MIRROR

Fluorescence properties of submonolayers of rhodamine 6G have been measured as a function of distance to an aluminum mirror. For distances less than 5 nm (spacer layers of 1 nm thickness were used) a broadening of the emission spectrum is observed. The fluorescence lifetime has been measured for distances up to 6 nm. The broadening of the fluorescence spectra and the shortening of the lifetime observed when the sample is close to the mirror are attributed to efficient energy transfer from the monolayer to the mirror. The experiments clearly demonstrate that both volume and surface contributions must be considered in this energy-transfer process.