A white organic light-emitting diode with ultra-high color rendering index, high efficiency, and extremely low efficiency roll-off

• Main Authors: Sun, Ning, Zhao, Yongbiao, Zhao, Fangchao, Chen, Yonghua, Yang, Dezhi, Chen, Jiangshan, Ma, Dongge
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electric apparatus and materials
• Online Access: https://hdl.handle.net/10356/102505; http://hdl.handle.net/10220/24275
• Institution: Nanyang Technological University

Ultra-high color rendering index (>90) is considered to be crucial for lighting in museum, studio, art gallery, medical, and wide-color-gamut display. However, all relevant works reported to exhibit ultra-high color rendering index suffer from a low efficiency and serious efficiency roll-off. In order to achieve ultra-high color rendering index and maintain high device efficiency at the same time, we incorporate four organic dyes in an elaborate device structure. The resulting white organic light-emitting diode exhibits rather high color rendering index up to 94 over a wide brightness range and yields electroluminescence efficiencies up to 14.2%, 26.0 cd/A, and 21.9 lm/W at the brightness of 1000 cd m−2, which are the highest values reported to date for such ultra-high color rendering index white organic light-emitting diodes. In addition, the current issue on efficiency roll-off is well resolved in the resulting device. The critical current density jc is as high as 203 mA cm−2.