Transient property of optically pumped organic film of different fluorescence lifetimes

The authors have investigated the direct relationship between the fluorescence lifetime (FL) and the transient photoluminescence (PL) response of organic materials to examine the applicability of organic light-emitting diodes as light sources for optical communications. Transient PL responses of organic materials with different FLs were measured as a frequency dependence of PL intensity pumped by a modulated violet laser diode. The authors have revealed that the cutoff frequency of PL intensity is significantly related to FL of an organic film. The -3 dB cutoff frequency of 1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]benzene (DSB) has reached about 160 MHz, which is much higher than that of other organic materials. This is because the FL of DSB is shortest among all the organic materials used in this study. (c) 2007 American Institute of Physics.