Organic Semiconductor Centre, EaStCHEM School of Chemistry , University of St Andrews , St Andrews , Fife KY16 9ST , U.K.
Organic Semiconductor Centre, SUPA, School of Physics and Astronomy , University of St Andrews , North Haugh , St Andrews , Fife KY16 9SS , U.K.
ACS Appl Mater Interfaces. 2018 Oct 3;10(39):33360-33372. doi: 10.1021/acsami.8b11136. Epub 2018 Sep 21.
A series of four novel deep-blue to sky-blue thermally activated delayed fluorescence (TADF) emitters (2CzdOXDMe, 2CzdOXD4MeOPh, 2CzdOXDPh, and 2CzdOXD4CFPh) have been synthesized and characterized. These oxadiazole-based emitters demonstrated bluer emission compared with the reference emitter 2CzPN thanks to the weaker acceptor strength of the oxadiazole moieties. The oxadiazole compounds doped in hosts (mCP and PPT) emitted from 435 to 474 nm with photoluminescence quantum yields ranging from 14-55%. The emitters possess singlet-triplet excited-state energy gaps (Δ E) between 0.25 and 0.46 eV resulting in delayed components ranging from 4.8 to 25.8 ms. The OLED device with 2CzdOXD4CFPh shows a maximum external quantum efficiency of 11.2% with a sky-blue emission at CIE of (0.17, 0.25), while the device with 2CzdOXD4MeOPh shows a maximum external quantum efficiency of 6.6% with a deep-blue emission at CIE of (0.15, 0.11).
已经合成并表征了一系列四种新型深蓝至天蓝色热激活延迟荧光（TADF）发射器（2CzdOXDMe、2CzdOXD4MeOPh、2CzdOXDPh 和 2CzdOXD4CFPh）。与参考发射器 2CzPN 相比，基于噁二唑的这些发射器由于噁二唑部分的吸电子能力较弱，表现出更蓝的发射。掺杂在主体（mCP 和 PPT）中的噁二唑化合物发射从 435nm 到 474nm，光致发光量子产率范围从 14%到 55%。发射器具有 0.25 到 0.46eV 之间的单重态-三重态激发态能隙（ΔE），导致延迟分量在 4.8 到 25.8ms 之间。带有 2CzdOXD4CFPh 的 OLED 器件在 CIE 为（0.17，0.25）的天蓝色发射时显示出最大外部量子效率为 11.2%，而带有 2CzdOXD4MeOPh 的器件在 CIE 为（0.15，0.11）的深蓝色发射时显示出最大外部量子效率为 6.6%。
