Cao Linyu, Li Jingjun, Zhu Zhi-Qiang, Huang Liang, Li Jian
Materials Science and Engineering, Arizona State University, Tempe, Arizona 85287, United States.
Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States.
ACS Appl Mater Interfaces. 2021 Dec 22;13(50):60261-60268. doi: 10.1021/acsami.1c17335. Epub 2021 Dec 7.
Stable and efficient emitters are highly desired for near-infrared organic light-emitting diodes (NIR OLEDs) due to their extensive applications in biometric authentication, night vision display, and telecommunication. As this technology advances, there is an increasing demand for the development of NIR OLEDs with an emission spectrum beyond 900 nm. This work reports a stable and efficient near-infrared Pt(II) porphyrin complex, i.e., Pt(II) tetra(3,5-difluorophenyl)tetranaphthoporphyrin named PtTPTNP-F, of which 84% of the total emitted photons are at wavelengths longer than 900 nm. By introducing fluorine atoms on the positions of all four phenyl groups, PtTPTNP-F can successfully overcome the common thermal instability issue emerging from the heavy Pt(II) porphyrin complexes, demonstrating a sublimation yield of above 90%. By carefully choosing the host materials, a NIR OLED device with PtTPTNP-F as an emissive material achieves a high peak device efficiency of 1.9%. Furthermore, devices of PtTPTNP-F fabricated in a stable device structure demonstrate extraordinary operational stability with an LT lifetime (time to 99% of the initial photocurrent) of more than 1000 h at a constant driving current density of 20 mA cm.
由于近红外有机发光二极管（NIR OLED）在生物特征认证、夜视显示和电信领域有着广泛应用，因此非常需要稳定且高效的发光体。随着这项技术的发展，对发射光谱超过900 nm的近红外OLED的开发需求日益增加。这项工作报道了一种稳定且高效的近红外铂（II）卟啉配合物，即四（3,5-二氟苯基）四萘卟啉铂（II），命名为PtTPTNP-F，其发射的光子中84%的波长大于900 nm。通过在所有四个苯基的位置引入氟原子，PtTPTNP-F能够成功克服重铂（II）卟啉配合物常见的热不稳定性问题，其升华产率超过90%。通过精心选择主体材料，以PtTPTNP-F作为发光材料的近红外OLED器件实现了1.9%的高峰值器件效率。此外，采用稳定器件结构制造的PtTPTNP-F器件在20 mA cm的恒定驱动电流密度下表现出非凡的工作稳定性，其LT寿命（光电流降至初始值99%的时间）超过1000小时。
