Highly Efficient New Hole Injection Materials for Organic Light Emitting Diodes Base on Phenothiazine Derivatives
作者:Beomjin Kim、Jaehyun Lee、Youngil Park、Changjun Lee、Jong Wook Park
DOI:10.1166/jnn.2014.8456
日期:2014.8.1
New hole injection materials for OLED based on phenothiazine were synthesized, and the electro-optical properties of synthesized materials were examined by through UV-Vis. and photoluminescence spectroscopy as well as cyclic voltammetry. 1-NDD-t-BPBP and 2-NDD-t-BPBP showed Tg of 180 and 177 °C. These are higher than that (110 °C) of 2-TNATA, commercial HIL material. As for the HOMO level of the synthesized materials, 1-NDD-t-BPBP and 2-NDD-t-BPBP were 4.99 and 5.02 eV, indicating well-matched values between HOMO (4.8 eV) of ITO and HOMO (5.4 eV) of NPB, HTL material. In addition, judging from the fact that the synthesized materials both barely showed any absorption in the range of over 450 nm, the synthesized materials could be effectively used as an HIL material. The synthesized materials were used as the HIL in OLED device, yielding luminance efficiencies of 4.51 cd/A (1-NDD-t-BPBP) and 4.44 cd/A (2-NDD-t-BPBP). These results indicated that 1-NDD-t-BPBP shows more excellent luminance efficiency which is about 11% improved over 2-TNATA a commercial HIL material.
基于苯噻嗪的新孔注入材料被合成,合成材料的电光性能通过紫外-可见光光谱、光致发光光谱以及循环伏安法进行了测试。1-NDD-t-BPBP和2-NDD-t-BPBP的玻璃化转变温度分别为180°C和177°C,均高于商业HIL材料2-TNATA的110°C。关于合成材料的HOMO能级,1-NDD-t-BPBP和2-NDD-t-BPBP分别为4.99和5.02 eV,表明它们的HOMO值与ITO的4.8 eV和HTL材料NPB的5.4 eV之间匹配良好。此外,从合成材料在450 nm以上的波长范围内几乎没有吸收的事实来看,合成材料可以有效作为HIL材料。合成材料被用作OLED器件中的HIL,产生的光致效率分别为4.51 cd/A(1-NDD-t-BPBP)和4.44 cd/A(2-NDD-t-BPBP)。这些结果表明,1-NDD-t-BPBP表现出更优越的光致效率,比商业HIL材料2-TNATA提高约11%。