[14a-2A-1~11] 12.3 Functional Materials and Novel Devices

△ [14a-2A-5] Study of intramolecular relaxation processes of organic laser dyes

〇Munetomo Inoue¹, Toshinori Matsushima^1,2, Chihaya Adachi^1,2 (1.Kyushu Univ. OPERA, 2.JST ERATO)

Keywords:Organic semiconductor,Laser,Singlet Triplet Annihialtion

One of the most serious problems to realize organic solid-state laser diodes (OLDs) is a rapid decrease in external quantum efficiency at high current densities, which is in-part due to the quenching of singlet excitons by populated triplet excitons, i.e., singlet-triplet annihilation (STA). The STA process competes with other radiative and nonradiative intramolecular relaxation processes. Therefore, we assume that the STA can be suppressed if radiative decay constants (k_r) of laser dyes are sufficiently large. To demonstrate this idea, we investigate how k_r affects STA characteristics.