Highly Efficient Spiro[fluorene-9,9′-thioxanthene] Core Derived Blue Emitters and Fluorescent/Phosphorescent Hybrid White Organic Light-Emitting Diodes
Highly Efficient Spiro[fluorene-9,9′-thioxanthene] Core Derived Blue Emitters and Fluorescent/Phosphorescent Hybrid White Organic Light-Emitting Diodes
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DOI：
10.1021/cm504441v
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发表时间：
2015-02-10
影响因子：
8.6
通讯作者：
Su, Shi-Jian
中科院分区：
文献类型：
--
作者：
Li, Yunchuan;Wang, Zhiheng;Su, Shi-Jian
设计并合成了一系列以螺[芴-9，9 '-噻吨]或螺[芴-9，9'-噻吨-S，S-二氧化物]为核，苯基咔唑或三苯胺为臂的蓝色发光体。它们的螺环构象有利于它们的热稳定性和降低聚集淬灭的趋势。通过调节硫原子的价态，得到了高效的局域激发态（LE）和电荷转移态（CT）蓝光发射体。基于LE发射体TPA-S和CzB-S作为非掺杂发射层的器件表现出1.76%和2.03%的高外量子效率以及国际照明委员会（CIE）坐标为（0.158，0.039）和（0.160，0.054），并且它们的CIEy值是所报道的深蓝色OLED的最小值之一，并且很容易非常接近无机发光二极管的CIEy值。CIE（0.16，0.02）]。基于CT发射体TPA-SO2作为发射层的非掺杂器件也表现出5.46 cd A（-1）的高电流效率和（0.154，0.168）的CIE坐标。为了充分利用25%的单线态激子和75%的三线态激子，还以TPA-SO 2作为蓝色发光体以及橙子磷光发光体的主体来制造单发射层结构中的荧光/磷光混合白色有机发光二极管，以给出47.9 lm W-1的前视功率效率，这是在不使用任何外耦合技术的类似结构中的器件所报道的最高值。
A series of blue emitters incorporating spiro[fluorene-9,9'-thioxanthene] or spiro[fluorene-9,9'-thioxanthene-S,S-dioxide] as the core and phenylcarbazole or triphenylamine as the arms were designed and synthesized. Their spiro conformation is beneficial for their thermal stability and for reducing the trend of aggregation quenching. By tuning the valence of the sulfur atom, highly efficient local excited (LE) state deep blue emitters and charge-transfer (CT) state blue emitters are obtained. The devices based on the LE emitters TPA-S and CzB-S as the nondoped emissive layer exhibit high external quantum efficiency of 1.76% and 2.03% and Commission Internationale de lEclairage (CIE) coordinates of (0.158, 0.039) and (0.160, 0.054), respectively, and their CIEy values are among the smallest ever reported for the deep blue OLEDs and are readily very close to that of the inorganic light-emitting diode [CIE (0.16, 0.02)]. The nondoped device based on the CT emitter TPA-SO2 as the emissive layer also exhibits a high current efficiency of 5.46 cd A(-1) and CIE coordinates of (0.154, 0.168). To fully utilize the 25% singlet and 75% triplet excitons, fluorescent/phosphorescent hybrid white organic light-emitting diodes in a single-emissive-layer architecture were also fabricated with TPA-SO2 as the blue emitter as well as the host of orange phosphorescent emitter to give forward-viewing power efficiency of 47.9 lm W-1, which is the highest value ever reported for the devices in a similar architecture without using any out-coupling technology.