Standard White CP‐OLEDs Performance Achieved by Intramolecular Chirality Transfer Mechanism through Polymer Chain

Abstract

In this work, a chiral functionalized bis‐benzoxanethonyl unit is introduced into three conjugated polymer backbones (S‐/R‐BP, S‐/R‐WP1, and S‐/R‐WP2) as the emitting layers (EMLs) of organic light‐emitting diodes (OLEDs) to construct full‐color circularly polarized electroluminescence (CP‐EL) by solution‐processing. Interestingly, standard white CP‐EL based on the monodispersed S‐/R‐WP2 achieves a high color rendering index of 95 at CIE coordinates of (0.33, 0.34). The CP‐OLED performances show the turn‐on voltage of ≈5.8 V, high maximum luminance of ≈3000 cd m−2, and stable gEL value of 10−3 in the wavelength range of 425–760 nm. This work is the first example to realize standard white CP‐OLEDs by intramolecular chirality transfer mechanism from chiral blue‐color moiety to achiral red‐color dye through polymer chain, which provides a valuable strategy to develop white CP‐EL for potential lighting and full‐color 3D displays.

Advances in circularly polarized luminescence materials based on helical polymers

“…54,55 Cheng et al introduced a chiral functionalized bis-benzoxanethonyl unit by intramolecular chiral transfer mechanism to prepare three conjugated polymer backbones (S-/R-BP, S-/R-WP1, and S-/R-WP2) to construct fullcolour CP-EL. 56 In addition, Chen et al synthesized a pair of linear axially chiral conjugated polymers by incorporating rigid axially chiral chromophores into the polymer backbones. 57 The twisted biphenyl skeleton effectively reduces the energy gap between the S1 and T, which greatly facilitates the intersystem crossing (ISC) process.…”

“…54,55 Cheng et al introduced a chiral functionalized bis-benzoxanethonyl unit by intramolecular chiral transfer mechanism to prepare three conjugated polymer backbones (S-/R-BP, S-/R-WP1, and S-/R-WP2) to construct full-colour CP-EL. 56…”

Polymer‐Based Circularly Polarized Luminescent Materials

“…Very recently, Cheng' group constructed emitting layers of standard white CP-OLEDs using chiral functionalized bisbenzoxanethonyl unit. [263] The devices could achieve Commission International d'Eclairage (CIE) coordinate of (0.33, 0.34), color rendering index of 95, and g EL intensity of about 10 −3 . In addition to the above examples, as shown in Figure 23B, [260] CPL materials with TADF properties have become an effective means to construct efficient CP-OLEDs, which has been described in Section 3.3.…”

Induced Red Circularly Polarized Luminescence Emission Promoted by Intermolecular Förster Resonance Energy Transfer through a Cholesteric Liquid Crystal Medium

“…Finally, the resulting solids were dried under vacuum to give DTBTF8 as a dark purple solid (29.7 mg, 21%). GPC: 66 The UV−vis absorption and fluorescence emission spectra of PCPH5 and DTBTF8 were tested in THF solution (Figure 1). The maximum absorption peak of PCPH5 was located at 307 nm, and the emission peak occurred at 480 nm upon excitation at 310 nm.…”