文献类型：期刊文献

英文题名：Effects of the emission layer structure on the electroluminescence performance of the white organic light emitting diodes based on thermally activated delayed fluorescence emitters

作者：Mu, Haichuan[1];Wang, Dingshu[1];Wang, Ruibin[2];Qian, Min[1];Xie, Haifen[1];Yao, Mengqiang[1]

机构：[1]East China Univ Sci & Technol, Sch Sci, Dept Phys, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Shanghai Jiao Tong Univ, Instrumental Anal Ctr, 800 Dongchuan Rd, Shanghai 200240, Peoples R China

年份：2020

卷号：53

期号：6

外文期刊名：JOURNAL OF PHYSICS D-APPLIED PHYSICS

收录：;EI(收录号：20200308042938);WOS:【SCI-EXPANDED(收录号:WOS:000526829200006)】；

基金：This work is supported by National Natural Science Foundation of China (Grant No. 61804054) and Natural Science Foundation of Shanghai (18ZR1410400).

语种：英文

外文关键词：WOLED; TADF; emission layer; decaying dynamics

摘要：White organic light emitting diodes (WOLED) employing blue, green and red thermally activated delayed fluorescence (TADF) emitters of DMAC-DPS(B), 4CzIPN(G) and 4CzTPN-Ph(R) and various emission layer (EML) structures of G/B, G/R/B and R:G(4CzTPN-Ph(R) doped in 4CzIPN(G) host)/B are fabricated and the effects of the EML structure, including EML thickness and 4CzTPN-Ph(R) dopant concentration, on the electroluminescence (EL) performance are investigated. It is found that the WOLED with the simple EML structure of G(20 nm)/B(10 nm) demonstrates maximum power efficiency (PE) around 16 lm/w and color rendering index (CRI) of 81. Meanwhile, R:G/B EML exhibits better EL performance than that of G/R/B EML. Especially, striking high CRI of 90 together with maximum PE around 13 lm/w can be obtained for R(1 wt%):G(20 nm)/B(10 nm) EML by meticulously modulation of EML thickness and 4CzTPN-Ph(R) dopant concentration, indicating the achievement of balance between EL efficiency and CRI for non-doped TADF emitter-based WOLED. Furthermore, the stacked EML of G(20 nm)/R(0.1 nm) and G(20 nm)/R( 0.1 nm)/B(10 nm) reveal much more serious obstruction of delayed fluorescence (DF) compared to mixed EML of R(1 wt%):G(20 nm) and R(1 wt%):G(20 nm)/B(10 nm), implying more intensified quenching effects from the sandwiched 0.1 nm 4CzTPN-Ph(R) layer which will lead to deterioration of EL performance. Different energy transfer routes are derived based on the transient photoluminescence decaying dynamics of R(1 wt%):G(20 nm)/B(10 nm) and G(20 nm)/R(0.1 nm)/B(10 nm) EML and the sandwiched 4CzTPN-Ph(R) ultrathin layer is found to be critical. The decaying dynamics responsible for such EML structure dependent EL performance is discussed in detail.