Die Temperaturabhängigkeit der sensibilisierten Fluoreszenz in Naphthalin-Kristallen zwischen 2 und 100° K

Abstract

The relative quantum yields of the fluorescence of the host (ν̄0 = 31474 cm-1), a shallow trap (X1, ν̄0= 31444 cm-1), and a guest (β-methyl-naphthalene, ν̄0=31059 cm-1) have been measured from 2 to 100°K in naphthalene crystals as host. The temperature dependence can be described quantitatively by a hopping model for the exciton diffusion. The hopping time of the exciton (tH ≌ 10-13 sec) is independent of the temperature. The freezing in of the β-methyl-naphthalene fluorescence at low temperatures is the result of the competition between the two traps (β-MN and X1). In addition, the fluorescence spectrum of β-methyl-naphthalene as a guest in naphthalene has been measured and analyzed.