Photo-stability of single terrylene molecules in 2,3-dimethylnaphthalene crystals

On the photo-stability of single molecules. Dibenzoterrylene in 2,3-dimethylnaphthalene crystals

“…The situation described above with DBT molecules is qualitatively different in comparison with that observed previously for Tr molecules in 2,3-DMN crystals [5]. First of all, in the 2,3-DMN crystals obtained under a helium atmosphere the thermally activated photo-bleaching was so fast that we were not able to detect any single Tr molecule already at 260 K [5].…”

“…First of all, in the 2,3-DMN crystals obtained under a helium atmosphere the thermally activated photo-bleaching was so fast that we were not able to detect any single Tr molecule already at 260 K [5]. Even in the case of 2,3-DMN crystals grown under an argon atmosphere, where we observed single Tr molecules at 270 K (because argon atoms block oxygen diffusion) as many as $56% (42 from among 75 studied) of Tr molecules were photo-bleached during the first 350 s of illumination (with k exc = 532 nm, power 55 kW/cm 2 , which provided for single Tr molecules comparable excitation conditions to those for DBT molecules in the present work), see Fig.…”

“…The procedure to grow 2,3-DMN crystals and details of our home-built confocal microscope were already presented in our previous Letters [4,5,15].…”

“…At temperatures above 250 K the structure of 2,3-DMN crystals is further disturbed by thermally activated 'dynamic disorder' manifested by jumps of the host molecules which preserve or invert their polarity [14]. We proposed [4,5], that this dynamic disorder may stimulate faster diffusion of oxygen molecules, if these molecules can reside inside the crystal.…”

“…In our recent Letters [4,5], we studied single terrylene (Tr) molecules in 2,3-dimethylnaphthalene (2,3-DMN) single crystals. It was found that Tr molecules were photo-stable in crystals obtained by co-sublimation of both components under an argon atmosphere, whereas they were photo-bleached (at temperatures above 250 K) in crystals obtained under a helium atmosphere.…”