Efficient polymer light-emitting diodes (PLEDs) based on chiral [Pt(C^N)(N^O)] complexes with near-infrared (NIR) luminescence and circularly polarized (CP) light

Abstract

Chiral NIR-light emitters [Pt(iqbt)(S-Ln)] (1–4) were used as dopants to produce CP-NIR-PLEDs displaying λem of 732 nm, ηMaxEQE of 0.87–0.93%, and gEL of up to 10−3.

Axially Chiral Bis-Cycloplatinated Binaphthalenes and Octahydro-Binaphthalenes for Efficient Circularly Polarized Phosphorescence in Solution-Processed Organic Light-Emitting Diodes

“…In the past two decades, the class of square-planar cyclometalated Pt­(II) complexes has been extensively investigated because of their interesting phosphorescence nature, − but there are only a finite number of chiral Pt­(II) complexes for the applications in CP-OLEDs. − In 2016, Brandt et al used helicene-based Pt­(II) complexes [Figure a, (C^N)*Pt­(O^O), C^N = ( P )/( M )-pyridinyl-helicene, O^O = β-diketones] to construct solution-processed CP-OLEDs, which have a high g EL (+0.22 and −0.38) but a low power efficiency (η P = 0.23 lm W –1 ) . After that Yan et al introduced −F and −CF 3 moieties at a pyridinyl-helicene ligand to increase the volatility and emission intensity for vacuum-evaporated CP-OLEDs (EQE = 18.8%, g EL = 1.6 × 10 –3 ). , Han et al [(N^C^N)­Pt­(≡R)*, N^C^N = 1,3-bis­(2-pyridyl, ≡R = ( R )/( S )-(+)-α-methylbenzylisocyanide, solution-processed CP-OLEDs, luminance efficiency η L = 0.84 cd A –1 , g EL ≈ 10 –4 ], Lee et al [(N^C^N)*Pt­(Cl), N^C^N = ( R )/( S )-1-(2-oxazoline)-3-(2-pyridyl)­phenylate, vacuum-evaporated CP-OLEDs, EQE = 9.7%, g EL = 1.2 × 10 –4 ], and Fu et al [Figure b, (C^N)­Pt­(N^O)*, C^N = 1-(benzo­[b]-thiophen-2-yl)-isoquinoline, N^O = ( R )/( S )-Schiff base ligands; solution-processed CP-OLEDs, EQE = 0.93%, g EL ≈ 10 –3 ] adopted point-chirality-ligand-based Pt­(II) complexes to fabricate CP-OLEDs. Qian et al further utilized a liquid crystal to improve the EL performance of point-chirality-ligand-based Pt­(II) complexes [(N^C)*Pt­(O^O), N^C = ( R )/( S )-2-phenylpyridine derivate, solution-processed CP-OLEDs, EQE = 11.3%, g EL = 0.02] .…”

Rational Design of the Platinahelicene Enantiomers for Deep-Red Circularly Polarized Organic Light-Emitting Diodes

“…CPL spectra of P-Pt and M-Pt were also preformed [Figure 3 (bottom)] to prove the chiroptical properties of the luminescent molecular upon excitations. The P-Pt shows negative CPL signals in 550-850 nm region while the M-Pt shows symmetrical signals in the same position with the |g PL | of about 6.0 × 10 −3 which is superior compared with the reported chiral Pt(II) complexes (Shen et al, 2014;Fu et al, 2019). In order to explore the application of materials in OLEDs, the CPL properties of P-Pt and M-Pt in doped films were also investigated.…”

Frontiers in chiral phosphorescent complexes for circularly polarized electroluminescence

“…6,7 Phosphorescent materials based on organometallic complexes show good stability and low efficiency roll-off at high luminance and are currently widely applied in the OLED industry. 8 Considering the remarkable device performance of phosphorescent materials, a series of chiral phosphorescent metal complexes including chiral europium (Eu(III)), [9][10][11] iridium (Ir(III)), [12][13][14][15][16] and platinum (Pt(II)) [17][18][19][20][21][22][23] complexes were developed and employed as emitters in CP-OLEDs.…”