Perylene microcrystallites embedded in polyvinyl alcohol fabricated by a precipitation method

Perylene microcrystallites with a wide range of the size were fabricated by a precipitation method. The microcrystallite size distribution was well expressed by a Gaussian function. The luminescence spectra and the luminescence decay times were measured at 7∼10 K. The luminescence decay depended strongly on the power of a laser used for photo-excitation. At weak excitation, the decay exhibited a few nano-second delay in the rise time but at the intense excitation, a sharp rise and a sharp decay (spike) were observed. Those results suggested the presence of strong interaction among microcrystallites. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)