Highly efficient white organic light-emitting diodes with single small molecular emitting material

Abstract

We demonstrate a highly efficient white organic light emitting device with fluorescent small molecule 4,4′-bis(9-(1-naphthyl)anthracene-10-yl)biphenyl (BUBH-3). With a simple device architecture of indium tin oxide/tris 4,4′,4″-tris-N-naphthyl-N-phenylamino-triphenylamine (60nm)∕N,N′-bis-(1–naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (10nm)/BUBH-3 (45nm)∕Alq3 (15nm)∕LiF (1nm)∕Al (150nm), a white light with CIEx,y color of (0.31,0.36) was generated. The device achieved one of the best single-emitting-material electroluminescence performance of white organic light-emitting devices with efficiencies of 7.0cd∕A and 3.17lm∕W at 6.9V.

Emitting materials based on phenylanthracene-substituted naphthalene derivatives for organic light-emitting diodes

“…existence of electromers or electroplexes in OLEDs usually leads to a red-shifted and broadened emission spectrum [16,21]. Therefore, these results imply the possibility of formation of electromers or electroplexes during the electroluminescence process in devices A and B [23]. Device B exhibits mainly the blue emission at 447 nm with the CIE coordinates of (0.…”

Pure aromatic hydrocarbons with rigid and bulky substituents as bipolar hosts for blue phosphorescent OLEDs

“…The intensive study of novel π-conjugated materials for more than forty years has resulted in impressive achievements in 20 organic electronics, which possesses potential of low cost, large area, flexibility and bio-compatibility. In the view of functionalmaterial development, pure aromatic hydrocarbons, an essential class of π-conjugated materials, are brilliant mainly due to their high thermal stability, intensive ultraviolet-visible (UV-vis) 25 absorption, strong fluorescence, and sometime balanced carrier conductivity.…”

“…Then due to their strong fluorescence, they have been adopted in the field of OLEDs as dopant emitters 1,14-16 and proved to be able to improve device stability 14 . Further studies demonstrated that pure aromatic hydrocarbons of anthracene 35 derivatives exhibit both electron and hole transporting properties [17][18][19] , and can be used as host emitter in OLEDs 20,21 . Due to their good conjugation and the lack of preferential moieties either for hole or for electron transport, pure aromatic hydrocarbons are expected to possess high and bipolar carrier 40 transport property, which is highly desired as host component in OLEDs, such as host for phosphors in phosphorescent OLEDs (PhOLED) [22][23][24] .…”

“…15 2 Experimental 2.1 Instrumentation and synthesis 1 H-NMRand 13 C-NMR spectra were measured on a Bruker Ultra Shield Plus 400 MHz or 100 MHz spectrometer. Ultravioletvisible (UV-Vis) and photoluminescence (PL) spectrometers 20 were recorded with Shimadzu UV-3600 spectrophotometer from 220 to 650 nm and a Shimadzu RF-5301PC fluorophotometer in the range of 280-700 nm, respectively. Low temperature PL (LTPL) spectra were measured by an Edinburgh Instruments FLS920 spectrometer.…”

“…For mTPFB and mDPFB, it can be seen that their HOMO and LUMO electrons are almost concentrated on the perihedral fluorene moieties, presenting obvious difference to the other two materials with para-linking mode. This is understandable, 20 because besides the break of conjugation between the core and the peripheral substitutions via sp 3 carbon-carbon connection in all these materials, the meta-linking mode in mTPFB and mDPFB can offer further steric hinderance, strengthening the conjugation breaking effect thus limiting the electron 25 delocalization. These results are consistent with the electrochemical experiments as discussed later.…”