Fine-Tuning of Photophysical and Electroluminescence Properties of Benzothiadiazole-Based Emitters by Methyl Substitution
Fine-Tuning of Photophysical and Electroluminescence Properties of Benzothiadiazole-Based Emitters by Methyl Substitution
复制标题
DOI：
10.1021/acs.joc.7b02127
复制
发表时间：
2017-11-03
影响因子：
3.6
通讯作者：
Jou, Jwo-Huei
中科院分区：
文献类型：
--
作者：
Pathak, Ambika;Thomas, K. R. Justin;Jou, Jwo-Huei
制备了新型的含甲基取代的苯并噻二唑基材料，并表征为用于电致发光应用的有前景的绿色/黄绿色发光体。染料表现出较短的波长吸收和发射相比，nonmethylated染料。当与远离供体的含有甲基的类似染料相比时，在供体侧上含有甲基的染料表现出吸收和发射的蓝移。甲基的空间位阻效应导致了给体和受体的非平面排列，抑制了分子内的电荷转移。所有的染料在发射光谱中都表现出局域态和电荷转移激发态杂化的溶致变色特性。由于甲基基团的作用，染料在固态下抑制了聚集体的形成。采用这些化合物作为主体发光体或掺杂发光体在合适的主体基质中制备了溶液处理的多层OLED器件，并表现出绿色/黄绿色电致发光，外量子效率高达4.6%（15.7 cd A（-1））。
New benzothiadiazole-based materials containing methyl substitution are prepared and characterized as promising green/yellowish green emitters for electroluminescent applications. The dyes exhibited shorter wavelength absorption and emission when compared to nonmethylated dyes. A dye containing methyl group on the donor side exhibited blue shift in absorption and emission when compared to the analogous dye containing methyl group away from donor. The steric effect exerted by the methyl group is responsible for the nonplanar arrangement of donor and acceptor, which inhibited the intramolecular charge transfer. All the dyes displayed solvatochromism in the emission spectra characteristic of hybridization of local and charge transfer excited states. Due to the benefit of methyl group, the dyes restrained the formation of aggregates in the solid state. Solution processed multilayered OLED device were fabricated employing these compounds either as host emitters or dopant emitters in suitable host matrix and exhibited green/yellowish green electro-luminescence with external quantum efficiency as high as 4.6% (15.7 cd A(-1)).