Singlet Exciton Interactions in Crystalline Naphthalene

摘要

The decay of prompt fluorescence in crystalline naphthalene at 300 K, excited by picosecond 266 nm pulse, has been studied as a function of excitation intensity. Experimental decay curves can be fitted only when the exponential distribution in depth of excitation and the radial (gaussian) intensity profile of the excitation are both taken into account. From analysis of decay at early time (<=5ns) a best fit value of the singlet-singlet annihilation rate constant is found gamma /sub SS/ = 4+-1)10 exp -10 cm exp 3 s exp -1 . If the reaction is diffusion-limited, this rate implies an average singlet diffusivity D/sub S/ = (2+-1)10 exp -4 cm exp 2 s exp -1 . (Atomindex citation 10:447481)