Record efficiency of 1000 nm electroluminescence from a solution-processable host-free OLED

Abstract

New ytterbium complexes K(Solv)x[Yb(Ln)2] (Solv = ethanol and/or water) with 2-tosylaminobenzilidene-aryaloylhydrazones (H2L1, aryloyl = benzoyl; H2L2, aryloyl = 2-naphtoyl) demonstrated high solubility and hole mobility (ca. 2.610-6 cm2V-1s-1), while their...

Efficient Red Organic Light Emitting Diodes of Nona Coordinate Europium Tris(β‐Diketonato) Complexes Bearing 4′‐Phenyl‐2,2′:6′,2′′‐Terpyridine

“…The higher EL performance of Eu‐2 based device could possibly be due to the presence of three terminal electron‐rich napthyl rings of β‐diketone leading to more balanced carrier transport than Eu‐1 having three phenyl rings. This is further supported by the very recent report on the EL performance of a ytterbium complex of 2‐(tosylamino)‐benzylidene‐N‐(2‐halobenzoyl)‐hydrazones where the substitution of a benzoyl ring with naphthyl resulted in a significant increase of the electron mobility (6.9×10 −7 vs. 1.7×10 −6 cm 2 V −1 s −1 ) [33] . It is important to note that the device performances of the present Eu‐2 based OLEDs are among the best reported in the literature [34] (Table 3 and Figure 11) so far with EQE exceeding 7.0 % at J=10 mA/cm 2 .…”

“…This is further supported by the very recent report on the EL performance of a ytterbium complex of 2-(tosylamino)-benzylidene-N-(2-halobenzoyl)-hydrazones where the substitution of a benzoyl ring with naphthyl resulted in a significant increase of the electron mobility (6.9 × 10 À 7 vs. 1.7 × 10 À 6 cm 2 V À 1 s À 1 ). [33] It is important to note that the device 3.5 2108 8.45 6.98 6.0 0.628, 0.308 [7] Eu-4 (5 wt.%):PBD (90 nm) À À 10.0 À 5.30 À [35] Eu-5 (90 nm):CBP:PBD À À 5.1 1.0 3.70 0.66,0.33 [36] Eu-6 ( Where BPhen = 4,7-diphenyl-1,10-phenanthroline; PBD = 2-(tert-butylphenyl)-5-biphenylyl-1,3,4-oxadiazole; CBP = 4,4'-N,N'-dicarbazole-biphenyl. The superscripts [a]-[e] have same meaning as in Table 2.…”

First Dual Red–Near-Infrared Emissive Solution-Processed Organic Light-Emitting Diode Based on Europium–Ytterbium Mixed-Ligand Complexes for Pulse Oximetry

“…The monometallic europium complex reaches a quantum yield of 31%. The ytterbium quantum yields equal to 0.5–0.9%, which are the typical values for ytterbium complexes in powders, ,− while the record values reach 5.8% for powders. , So, the record efficiencies of the Yb-based OLED was obtained from the complex with the QY = 0.6–1.4%. , Noteworthy, these values for Eu–Yb solid solutions are comparable or even exceed the value for the monometallic compound. The ytterbium QY reaches the highest value of 0.9% within the Eu 0.02 Yb 0.98 (dbm) 3 BPhen compound.…”

“…Ytterbium electroluminescence of OLEDs B–D demonstrated rather high irradiance (Figure b). Eu 0.05 Yb 0.95 (dbm) 3 BPhen-based OLED B reached 19 μW/cm 2 , which is one of the highest among all the solution-processed Yb-based OLEDs. ,, …”

Ytterbium 10-carboxyperylene-3,4,9-tricarboxylates for targeted NIR luminescent bioimaging

“…They demonstrate narrow bands, a large ligand-induced Stokes' shift, and long lifetimes of lanthanides, as well as high absorption (log ε ∼ 4-5) due to the highly absorbing organic ligand in their composition. [9][10][11][12] NIR-emitting lanthanide compounds have relatively low quantum yields (up to 5-6% [13][14][15][16] in powders, but usually ∼1% [17][18][19][20] ) due to the ease of quenching, but their luminescence is still intense due to high absorption. This distinguishes them from currently actively developed in vivo bioimaging agents based on the upconversion nanoparticles (UCNPs; quantum yield is also typically around 1% 21 ), which require high excitation power densities (P exc > 20 W cm −2 ) due to poor absorption.…”