Photo-Crosslinking of Pendent Uracil Units Provides Supramolecular Hole Injection/Transport Conducting Polymers for Highly Efficient Light-Emitting Diodes

Polymers

Hsi-Kang Shih²  Yi-Han Chen²  Yu-Lin Chu²  Chih-Chia Cheng¹  Feng-Chih Chang²  Chao-Yuan Zhu²  Shiao-Wei Kuo³ 

[1] Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei City 10607, Taiwan; E-Mail:;Institute of Applied Chemistry, National Chiao Tung University, HsinChu, 30010, Taiwan; E-Mails:;Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan

关键词: photo-crosslinking;    uracil;    hole injection/transport;    phosphorescence;    OLED;   

DOI  :  10.3390/polym7050804

来源: mdpi

【 摘 要 】

A new process for modifying a polymeric material for use as a hole injection transport layer in organic light-emitting diodes has been studied, which is through 2π + 2π photodimerization of a DNA-mimetic π-conjugated poly(triphenylamine-carbazole) presenting pendent uracil groups (PTC-U) under 1 h of UV irradiation. Multilayer florescence OLED (Organic light-emitting diodes) device with the PTC-U-1hr as a hole injection/transport layer (ITO (Indium tin oxide)/HITL (hole-injection/transport layer) (15 nm)/N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) (15 nm)/Tris-(8-hydroxyquinoline)aluminum (Alq₃) (60 nm)/LiF (1 nm)/Al (100 nm)) is fabricated, a remarkable improvement in performance (Q_max (external quantum efficiency) = 2.65%, B_max (maximum brightness) = 56,704 cd/m², and LE (luminance efficiency)_max = 8.9 cd/A) relative to the control PTC-U (Q_max = 2.40%, B_max = 40,490 cd/m², and LE_max = 8.0 cd/A). Multilayer phosphorescence OLED device with the PTC-U-1hr as a hole injection/transport layer (ITO/HITL (15 nm)/Ir(ppy)₃:PVK (40 nm)/BCP (10nm)/Alq₃ (40 nm)/LiF (1 nm)/Al (100 nm)) is fabricated by successive spin-coating processes, a remarkable improvement in performance (Q_max = 9.68%, B_max = 41,466 cd/m², and LE_max = 36.6 cd/A) relative to the control PTC-U (Q_max = 8.35%, B_max = 34,978 cd/m², and LE_max = 30.8 cd/A) and the commercial product (poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) PEDOT:PSS (Q_max = 4.29%, B_max = 15,678 cd/m², and LE_max = 16.2 cd/A) has been achieved.

【 授权许可】

CC BY   
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