FLUORESCENCE OF PLASMA POLYMER-FILMS WITH EMBEDDED DYE MOLECULES

Plasma polymer thin films with embedded dye molecules (Rhodamine 6G) w ere deposited by alternating or simultaneous plasma polymerization and dye molecule sublimation. From films with different amounts of embedd ed dye molecules, fluorescence spectra as well as excitation spectra w ere recorded. At samples with very low amounts of embedded dye molecul es, the fluorescence band was found at lambda(f)l = 550...560 nm. At h igher dye amounts, the fluorescence band shifts to lambda(f)l = 590... 600 nm. This was interpreted as the change from embedded isolated dye molecules at low concentrations to dye molecule clusters or nanocrysta llites at higher concentrations. The appearance of a second fluorescen ce band at lambda(f)l = 680...700 nm was interpreted as a result of a chemical modification of the Rhodamine 6G molecules during plasma poly mer deposition. (C) 1998 Elsevier Science Ltd. All rights reserved.