Blue-Hazard-Free Organic Light-Emitting Diode with a Lifetime Greater than 200,000 h

Abstract

Blue-hazard-free lighting is in urgent need in order to protect human eyes and physiology. A candlelight-style organic light emitting diode (OLED) is so far the safest measure for its blue-hazard-free, low-color-temperature illumination. However, lifetime is still the most critical reliability issue in OLEDs, especially in lighting applications that are closely associated with high current density operation. Here, we present a novel approach to develop blue-hazard-free OLEDs with a lifetime exceeding 200,000 h at 1000 cd/m2 by employing a tandem structure with ultra-high purity emitter. The resultant device shows a current efficacy of 37.4 cd/A, an external quantum efficiency (EQE) of 22.7%, an 80 CRI, and a 78 SRI with a 223,500 h lifetime (t50). Additionally, the resultant device also exhibits a long retina exposure duration of 12,300 s (3.42 h) and suppresses very less melatonin generation (1.7%), demonstrating that the fabricated OLED device is a highly prospective general lighting source to safeguard human health.

Exciton regulation mechanism of Alq₃/HAT-CN tandem electroluminescent devices

“…其中MEL的低磁场快速上升主要归因 于磁场抑制的极化子对间ISC [16,17] . MC的低磁场 磁场范围快速增大 [32,33] . 而MEL和MC的高磁场 缓慢上升来源于TQA散射过程 [18] , 其详细的解 MEL (25 mT) 和MC LFE = MC (300 mT) − MC (25 mT) [33] .…”

“…MC的低磁场 磁场范围快速增大 [32,33] . 而MEL和MC的高磁场 缓慢上升来源于TQA散射过程 [18] , 其详细的解 MEL (25 mT) 和MC LFE = MC (300 mT) − MC (25 mT) [33] . 而导致TQA的增强, 这将造成MEL和MC上升 幅度随温度的降低而增大 [37] .…”

“…其 的降低MEL和MC上升幅度也随之减小, 即TQA 减少, TTA增强 [31] . 这归因于温度降低后Alq 3 / HAT-CN叠层OLED中载流子的迁移率变小, 注 入到器件中的载流子浓度相对降低, 电荷被T 1 散 射的概率降低 [15,33] , 磁场对TQA的抑制减弱, 导…”