Enhanced π-conjugation in hybridized local and charge transfer emitters for efficient red OLEDs and bioimaging

IF 4.3 2区化学 Q1 SPECTROSCOPY

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Pub Date : 2025-03-08 DOI:10.1016/j.saa.2025.126021

Qian Yan , Runhua Yao , Hongfei Han , Ruiqiang Hang , Hua Wang

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Abstract

Red-emitting materials have significantly advanced the development of materials for OLEDs and bioimaging. However, traditional red dyes often suffer from the 5 % external quantum efficiency (EQE) limit and aggregation-caused quenching (ACQ), which impede their practical applications. Herein, two red-emitting materials, TPA-QP and Cz-Ph-QP were designed and synthesized with donor–acceptor (D-A) structures. The ratio of localized π-conjugation to intramolecular charge transfer components was rationally adjusted due to the different spatial configurations of the donor units. Both emitters exhibited hybridized local and charge transfer (HLCT) characteristics and the higher planarity of the TPA-QP molecular structure enhanced π-conjugation and facilitated effective hybridization between the locally excited (LE) and charge transfer (CT), resulting in deep-red (DR) emission at 680 nm and high photoluminescence quantum yields of 15.6 %. Furthermore, TPA-QP-based OLED demonstrated emission closer to the standard saturated red (λ = 657 nm, CIE coordinates of (0.65, 0.33)) with an excellent maximum EQE of 6.47 % and low efficiency roll-off. Additionally, the fabricated nanoparticles (TQ NPs) showed deep-red emission (λ = 682 nm) and were successfully applied in cellular imaging. The results provide deeper insights into the effects of spatial configuration changes on promoting the luminescence performance of the long-wavelength HLCT molecules.

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来源期刊

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 物理-光谱学

CiteScore

8.40

自引率

11.40%

发文量

1364

审稿时长

40 days

期刊介绍： Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy (SAA) is an interdisciplinary journal which spans from basic to applied aspects of optical spectroscopy in chemistry, medicine, biology, and materials science. The journal publishes original scientific papers that feature high-quality spectroscopic data and analysis. From the broad range of optical spectroscopies, the emphasis is on electronic, vibrational or rotational spectra of molecules, rather than on spectroscopy based on magnetic moments. Criteria for publication in SAA are novelty, uniqueness, and outstanding quality. Routine applications of spectroscopic techniques and computational methods are not appropriate. Topics of particular interest of Spectrochimica Acta Part A include, but are not limited to: Spectroscopy and dynamics of bioanalytical, biomedical, environmental, and atmospheric sciences, Novel experimental techniques or instrumentation for molecular spectroscopy, Novel theoretical and computational methods, Novel applications in photochemistry and photobiology, Novel interpretational approaches as well as advances in data analysis based on electronic or vibrational spectroscopy.