利用叠层结构提高近紫外有机发光二极管的电致发光效率与稳定性  

Boosting Electroluminescence Efficiency and Stability of Near Ultraviolet Organic Light-emitting Diodes by Using Tandem Structure

作　　者：于宏宇 张宝文 陈平 张勇 YU Hongyu;ZHANG Baowen;CHEN Ping;ZHANG Yong(Chongqing Key Laboratory of Micro&Nano Structure Optoelectronics,School of Physical Science and Technology,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学物理科学与技术学院,微纳结构光电子学重庆市重点实验室,重庆400715

出　　处：《发光学报》2025年第2期315-325,共11页Chinese Journal of Luminescence

基　　金：重庆CSTC自然科学基金(CSTB2022NSCQ-MSX0438)。

摘　　要：在过去十年中,近紫外有机发光二极管(NUV-OLEDs)因其具有近紫外光子发射能力而受到研究者的广泛关注。然而,当器件的电致发光波长降至400 nm以下时,如何提升器件的辐射功率成为技术挑战。本研究采用BCPO和TAZ作为NUV发光材料,制备了单层和叠层NUV-OLEDs,并比较了它们的电致发光性能。结果表明,叠层器件的性能显著优于单层器件。其中,BCPO单层器件的发光峰位波长为384 nm,近紫外光占比56.9%,外量子效率2.91%,辐射功率34.2 mW/cm^(2);而BCPO叠层器件的近紫外光占比提高到60.5%,外量子效率提高到5.73%,辐射功率达到52.8 mW/cm^(2)。TAZ单层器件的发光峰位波长为377 nm,近紫外光占比79.1%,外量子效率3.65%,辐射功率15.7 mW/cm^(2);而TAZ叠层器件的近紫外光占比略增至79.6%,外量子效率提高到7.21%,辐射功率达到29.4 mW/cm^(2)。此外,叠层器件在相同辐射功率下所需电流密度更低,这使得叠层器件能够展现出比单层器件更好的发光稳定性。During the last ten years,near ultraviolet organic light-emitting diodes(NUV-OLEDs)have been widely concerned by researchers due to their NUV photon-emitting capability.However,when the electroluminescence(EL)wavelength is extended below 400 nm,how to increase the radiance of devices has become a technical challenge.In this research,small molecules of BCPO and TAZ with wide bandgap were used as the luminescent material.Then,NUV-OLEDs based on BCPO and TAZ with single unit and tandem structure were fabricated,respectively.And their EL properties were compared.The measurement results show that the EL performance of double unit tandem NUV-OLEDs is significantly better than that of single unit NUV-OLEDs.Single unit BCPO-based NUVOLEDs showed the maximum external quantum efficiency(EQE_(max))of 2.91% and the maximum radiance(R_(max))of 34.2 mW/cm^(2).The peak wavelength(λ_(EL))was 384 nm and the proportion of NUV light with wavelength below 400 nm(P_(NUV))was 56.9% in their EL spectra.In comparison,double unit BCPO-based tandem NUV-OLEDs showed EQE_(max)=5.73%,R_(max)=52.8 mW/cm^(2),λ_(EL)=384 nm,and P_(NUV)=60.5%.Single unit TAZ-based NUV-OLEDs showed EQE_(max)=3.65%,R_(max)=15.7 mW/cm^(2),λ_(EL)=377 nm,and P_(NUV)=79.1%.In comparison,double unit TAZbased tandem NUV-OLEDs showed EQE_(max)=7.21%,R_(max)=29.4 mW/cm^(2),λ_(EL)=377 nm,and P_(NUV)=79.6%.In addition,tandem NUV-OLEDs exhibited better luminescence stability than that of single unit devices because of the significantly lower current density required for tandem NUV-OLEDs compared to single unit NUV-OLEDs.

关 键 词：有机发光二极管 近紫外光 叠层结构 电荷生成层 

分 类 号：O473[理学—半导体物理] O475[理学—物理]