Excimer-emitting single molecules with stacked π-conjugated groups covalently linked at the 1,8-positions of naphthalene for highly efficient blue and green OLEDs
作者:Jian-Yong Hu、Yong-Jin Pu、Yusuke Yamashita、Fumiya Satoh、So Kawata、Hiroshi Katagiri、Hisahiro Sasabe、Junji Kido
DOI:10.1039/c3tc30319e
日期:——
Two efficient blue-light-emitting compounds, 1,8-bis(4-(N-carbazolyl)phenyl)naphthalene (BCzPN) and 1,8-bis(4-(10-phenylanthracen-9-yl)-phenyl)naphthalene (BPAPN), are designed and synthesized, in which two phenylcarbazole or diphenylanthracene units are closely stacked through bonding to the 1- and 8-positions of the naphthalene ring, resulting in strong intramolecular excimer emissions in solution or as a film. By utilizing BPAPN as an emitter, high efficiencies of 6 cd Aâ1 and 5.8% external quantum efficiency (EQE) at 100 cd mâ2, and 8 cd Aâ1 and 5.8% EQE at 1000 cd mâ2 are achieved in a non-doped blue device. By using BCzPN or BPAPN as a host, a DPAVBi-doped BCzPN based blue device gave high efficiencies of 15 cd Aâ1 and 6.5% EQE at 100 cd mâ2, and 12 cd Aâ1 and 5.5% EQE at 1000 cd mâ1, and a C545T-doped BPAPN based green device gave high efficiencies of 23 cd Aâ1 and 6.7% EQE at 100 cd mâ2, and 22 cd Aâ1 and 6.7% EQE at 1000 cd mâ2, respectively.
两种高效蓝光化合物,1,8-双(4-(N-咔唑基)苯基)萘(BCzPN)和1,8-双(4-(10-苯基蒽-9-基)-苯基)萘(BPAPN),是设计和合成的,其中两个苯基咔唑或二苯基蒽单元通过键合到萘环的1-和8-位而紧密堆叠,从而在溶液或薄膜中产生强烈的分子内准分子发射。通过利用 BPAPN 作为发射极,在 100 cd m-2 时可实现 6 cd A-1 的高效率和 5.8% 的外量子效率 (EQE),在 1000 cd m-2 时可实现 8 cd A-1 和 5.8% EQE 的高效率图2是在非掺杂蓝色器件中实现的。通过使用 BCzPN 或 BPAPN 作为主体,基于 DPAVBi 掺杂的 BCzPN 蓝色器件在 100 cd m-2 下具有 15 cd A-1 和 6.5% EQE 的高效率,在 100 cd m-2 下具有 12 cd A-1 和 5.5% EQE 的高效率在 1000 cd m-1 时,基于 C545T 掺杂的 BPAPN 的绿色器件在 100 cd m-2 时具有 23 cd A-1 和 6.7% EQE 的高效率,在 100 cd m-2 时具有 22 cd A-1 和 6.7% EQE 的高效率分别为 1000 cd m±2。