[21p-S423-1~19] 13.9 Optical properties and light-emitting devices

[21p-S423-6] Fluorescence lifetime fluctuation: A new approach to emission mechanism

〇Masashi Ishii¹, Ryo Yoshimatsu², Naoto Hirosaki¹, Koutoku Ohmi³ (1.NIMS, 2.Denka, 3.Tottori Univ.)

Keywords:fluorescence lifetime,fluctuation,fluorescent materials

Although fluorescence lifetime measurement is a practical technique to analyze emission centers, we frequently approximate the decay curve with physically ambiguous functions such as KWW function. In order to progress well-grounded modeling of the relaxation process, we proposed a new analytical method, fluorescence lifetime fluctuation (FLF) which deals with statistical distribution of the decay time.In the FLF method, fluorescence decay after a rectangular wave photoexcitation was traced with a photodiode. The decay signal was introduced into a comparator to generate a “stop” signal at a preset emission-intensity. The time interval between a “start” signal (trailing edge of the rectangular wave photoexcitation) and the stop signal was recorded with a time interval analyzer. The analyzer provided a histogram of the time intervals for 25000 photoexcitation shots. In this presentation, we show actual results of FLF, and propose a unique excitation/relaxation model involved in new fluorescent materials.