Regulating charge and exciton distribution in high-performance hybrid white organic light-emitting diodes with n-type interlayer switch

• Main Authors: Luo, Dongxiang, Yang, Yanfeng, Xiao, Ye, Zhao, Yu, Yang, Yibin, Liu, Baiquan
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2018
• Subjects: White Light; Hybrid; DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/88361; http://hdl.handle.net/10220/45780
• Institution: Nanyang Technological University

The interlayer (IL) plays a vital role in hybrid white organic light-emitting diodes (WOLEDs); however, only a negligible amount of attention has been given to n-type ILs. Herein, the n-type IL, for the first time, has been demonstrated to achieve a high efficiency, high color rendering index (CRI), and low voltage trade-off. The device exhibits a maximum total efficiency of 41.5 lm W−1, the highest among hybrid WOLEDs with n-type ILs. In addition, high CRIs (80–88) at practical luminances (≥1000 cd m−2) have been obtained, satisfying the demand for indoor lighting. Remarkably, a CRI of 88 is the highest among hybrid WOLEDs. Moreover, the device exhibits low voltages, with a turn-on voltage of only 2.5 V (>1 cd m−2), which is the lowest among hybrid WOLEDs. The intrinsic working mechanism of the device has also been explored; in particular, the role of n-type ILs in regulating the distribution of charges and excitons has been unveiled. The findings demonstrate that the introduction of n-type ILs is effective in developing high-performance hybrid WOLEDs.