[11a-S222-1~12] 12.4 Organic light-emitting devices and organic transistors

[11a-S222-4] Stability Enhancement of Excited States in Organic Thin Films by Addition of Triplet Quenchers

〇Toshinori Matsushima^1,2,3, Seiya Yoshida^2,3, Ko Inada^2,3, Yu Esaki^2,3, Toshiya Fukunaga^2,3, Hiroyuki Mieno^2,3, Nozomi Nakamura^2,3, Fatima Bencheikh^2,3, Matthew R. Leyden^2,3, Ryutaro Komatsu^2,3, Chuanjiang Qin^2,3, Atula S. D. Sandanayaka^2,3, Chihaya Adachi^1,2,3 (1.I2CNER, Kyushu Univ., 2.OPERA, Kyushu Univ., 3.JST ERATO)

Keywords:Organic laser, Triplet quencher, Photodegradation

The organic material 4,4’-bis[(N-carbazole)styryl]biphenyl (BSBCz) is an excellent gain medium for laser devices. However, BSBCz laser output quickly degrades during photoexcitation, which is an issue that must be overcome before it can be used for practical applications. In this study, we investigated the photodegradation mechanisms of BSBCz with the aim of enhancing its excited-state stability. We attribute the photodegradation of BSBCz to instability of the triplet excited states that would occasionally decompose into other species. This decomposition reduces absorption and introduces exciton quenchers. Incorporating the triplet managing material 9,10-di(naphtha-2-yl)anthracene (ADN) into BSBCz films greatly improves photoluminescence and amplified spontaneous emission stability because of the effective removal of the unstable triplets by ADN. This triplet managing method makes it possible to increase operational stability for BSBCz-based organic light-emitting diodes. Therefore, these results will contribute toward the fabrication of stable optically and electrically pumped organic laser diodes.