Organic light-emitting diodes with a spacer enhanced exciplex emission

• Main Authors: Yan, Fei, Chen, Rui, Sun, Handong, Sun, Xiao Wei
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Molecular electronics
• Online Access: https://hdl.handle.net/10356/104097; http://hdl.handle.net/10220/19511
• Institution: Nanyang Technological University

By introducing a spacer molecule into the blended exciplex emissive layer, the performance of the bulk heterojunction exciplex organic light-emitting diodes (OLEDs) was improved dramatically; the maximum luminous efficiency was enhanced by about 22% from 7.9 cd/A to 9.7 cd/A, and the luminous efficiency drop was reduced by 28% at 400 mA/cm2. Besides the suppressed annihilation of exciton, the time-resolved photoluminescence measurements indicated that the spacer enhanced the delayed fluorescence through increasing the backward intersystem crossing rate from the triplet to singlet exciplex state. This method is useful for developing high performance exciplex OLEDs.