Highly efficient, deep-red organic light-emitting devices using energy transfer from exciplexes

Abstract

Record-breaking highly efficient, deep-red phosphorescent OLEDs are developed. The optimized device exhibits an external quantum efficiency of nearly 18% and an electroluminescence emission wavelength of 670 nm.

A Novel Sterically Bulky Hole Transporter to Remarkably Improve the Lifetime of Thermally Activated Delayed Fluorescent OLEDs at High Brightness

“…To evaluate the performance of novel HTLs, three types of OLED devices based on 4CzIPN were fabricated with the structure of [ITO (100 nm)/triphenylamine‐containing polymer: 4‐isopropyl‐4‐methyldiphenyl‐iodonium tetrakis(pentafluorophenyl)borate (PPBI) (20 nm)/HTL (20 nm)/mCBP: 15 wt % 4CzIPN (30 nm)/DBT‐TRZ (10 nm)/1,4‐di(1,10‐phenanthrorin‐2‐yl)benzene (DPB): 20 wt % 8‐quinolinolato lithium (Liq) (40 nm)/2‐(2′,2′′‐bipyridine‐6′‐yl)phenolate (Libpp) (1 nm)/Al] (Device 1). We used DBT‐TRZ as the hole‐blocking layer and DPB as the ETL in order to obtain long operation stability (Figure ). Moreover, Liq and Libpp were used for the electron‐injection layer to realize a low driving voltage.…”

“…NPD and Liq were purchased from e‐Ray Optelectronics Technology Co., Ltd. DBTPB was purchased from Luminescence Technology Corp. mCBP, 4CzIPN, DBT‐TRZ, DPB, and Libpp were prepared according to previous report. All organic materials were purified by temperature gradient sublimation in vacuum.…”

Unique Solid‐State Emission Behavior of Aromatic Difluoroboronated β‐Diketones as an Emitter in Organic Light‐Emitting Devices

“…Because the neatf ilms exhibited relatively inferior h PL values of approximately 31 %, we investigated the photophysical properties of codeposited films of 3-Phe@Ph to obtain higher h PL values. Additionally,a se xpectedf rom the photophysical properties, it was essential to select an appropriate hostm aterial that did not exhibit strong intermolecular interactions with 3-Phe@Ph.T herefore, we tested four different types of host materials,b is[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), [14] [15] N,N-dicarbazoyl-3,5benzene (mCP), and 4,4,4-tris(N-carbazolyl)triphenylamine (TCTA), and fabricated films doped with 3wt% 3-Phe@Ph to measuret he PL spectra and h PL values. Figure 2aa presents the PL spectra of the 3wt% 3-Phe@Ph-doped DPEPO, DBT-TRZ, and mCP films and the neat 3-Phe@Ph film, and Figure 2bb presents photographs of the 3wt% 3-Phe@Ph-doped films on quartz substrates under UV irradiation (l = 254 nm).…”

“…[7,8] NPD and TCTA were purchased from eRay.m CP was purchased from Lumtec. DPEPO, [14] and DBT-TRZ [15] and B3PyPB [16] were synthesized according to literature procedures. All organic materials were purified by using temperature-gradient sublimation in vacuum.…”

Recent progress of pyrimidine derivatives for high-performance organic light-emitting devices

“…Another types of pyramidine-based n-type host are used in stable deep-red OLEDs with EL emission wavelength of 670 nm. Nagai et al 63 developed dibenzothiophene-containing n-type host materials named 2-…”