Abstract
We fabricated highly efficient blue organic light-emitting diodes (OLEDs) by designing differing emitting layer structures with fluorescent host and dopant materials of 4,4-bis (2,2-diphenylyinyl)-1,10-biphenyl and 9,10-bis (2-naphthyl) anthracene as host materials and 4,4’-bis (9-ethyl-3-carbazovinylene)-1,1’biphenyl (BCzVBi) as a dopant material to demonstrate electrical and optical improvements. Best enhancement in luminance and luminous efficiency were achieved by a quantum well structure in device F with 8668 cd/m 2 at 8 V and 5.16 cd/A at 103.20 mA/cm 2 , respectively. Among the blue OLED devices doped by BCzVBi, device B emits the deepest blue emission with Commission Internationale de l’É clairage coordinates of (0.157, 0.117) at 8 V.
Highlights
Organic light-emitting diodes (OLEDs) have attracted considerable interests due to their potential uses, such as full-color displays and solid-state lighting,[1,2,3] when Tang and Van Slyke[4] reported the first multilayered OLEDs
Even though it is reported that some blue OLEDs emit a pleasing deep blue color, still efficiency remains an issue that should be improved in order to obtain lower power consumption
The standard device structure used in this study is as follows: Indium tin oxide (ITO)/N,N’-diphenyl-N,N’-bis (1-napthyl)-1,1’-biphenyl-4,4’-diamine (NPB) as a hole-transport layer (HTL) (700 Å)/emitting layer (EML) (300 Å)/4,7-diphenyl-1,10-phenanthroline (BPhen) as an electron transport layer (ETL) (300 Å)/lithium quinolate (Liq) as an electron injection layer (20 Å)/aluminum (1000 Å)
Summary
Organic light-emitting diodes (OLEDs) have attracted considerable interests due to their potential uses, such as full-color displays and solid-state lighting,[1,2,3] when Tang and Van Slyke[4] reported the first multilayered OLEDs. The fluorescent OLED’s efficiency is usually lower than a phosphorescent OLED, making it a challenge to improve its efficiency to the level of phosphorescent OLEDs. It is widely known that a host–dopant system can greatly improve device performance in terms of EL luminous efficiency and color stability.[10] better matching between the host material and deep blue dopant material with sufficient spectral overlap for Förster energy transfer[11] is required for deep blue emission with high efficiency.[12,13,14,15,16,17,18,19,20] an OLED’s quantum efficiency is determined. Variable combinations of host and dopant in single and dual EMLs were observed in blue OLED devices and their electrical and optical characteristics were compared to each other to achieve best luminous efficiency and blue color coordinates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
