Boosting Efficiency of Near‐Infrared Organic Light‐Emitting Diodes with Os(II)‐Based Pyrazinyl Azolate Emitters
作者:Yi Yuan、Jia‐Ling Liao、Shao‐Fei Ni、Alex K.‐Y. Jen、Chun‐Sing Lee、Yun Chi
DOI:10.1002/adfm.201906738
日期:2020.1
(NIR) emitters and to improving the performance of NIR organic light‐emitting diodes (OLEDs). Os(II) complexes are known to be an important class of NIR electroluminescent materials. However, the highest external quantum efficiency achieved so far for Os(II)‐based NIR OLEDs with an emission peak wavelength exceeding 700 nm is still lower than 3%. A new series of Os(II) complexes (1–4) based on functional
Highly Efficient Near‐Infrared Electroluminescence up to 800 nm Using Platinum(II) Phosphors
作者:Sheng Fu Wang、Yi Yuan、Yu‐Chen Wei、Wei‐Hsiang Chan、Li‐Wen Fu、Bo‐Kang Su、I‐Yun Chen、Keh‐Jiunh Chou、Po‐Ting Chen、Hsiu‐Fu Hsu、Chang‐Lun Ko、Wen‐Yi Hung、Chun‐Sing Lee、Pi‐Tai Chou、Yun Chi
DOI:10.1002/adfm.202002173
日期:2020.7
chelate, and strong intermolecular interaction and high crystallinity in vacuum‐deposited thin films engender strong intermolecularchargetransfer transition including metal–metal‐to‐ligand chargetransfer; thereby, exhibiting efficient photoluminescence within 776–832 nm and short radiative lifetimes of 0.52–0.79 µs. Consequently, nondoped NIR‐emitting OLEDs based on these Pt(II) complexes are fabricated
近红外有机发光二极管(NIR OLED)可实现许多独特的应用,从夜视显示器到光动力疗法。但是,开发具有低效率滚降的高效NIR OLED仍然具有挑战性。此处,一系列新的杂合铂(II)配合物(1 - 4)两侧由两个吡啶基pyrimidinate和功能azolate螯合物合成。减少的ππ*吡啶嘧啶吡啶鎓螯合物的能隙,以及真空沉积薄膜中的强分子间相互作用和高结晶度,导致强的分子间电荷转移跃迁,包括金属到金属到配体的电荷转移;因此,在776-832 nm范围内显示出有效的光致发光,辐射寿命短,为0.52-0.79 µs。因此,制造了基于这些Pt(II)配合物的非掺杂NIR发射OLED,Pt(II)配合物2和4分别在794 nm和803 nm处具有创纪录的最大外部量子效率,分别为10.61%和9.58%。此外,还观察到了低效率滚降,其中器件效率为2和4比以100 mA cm -2的电流密度记录的最佳近红外发射OLED高至少四倍。