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. 2023 Feb 10;13(8):5317-5323.
doi: 10.1039/d3ra00083d. eCollection 2023 Feb 6.

Two-photon absorption behavior of conjugated oligomers suitable for low colour temperature LEDs

Tianhao Huang  1 , Chengzi Jiang  2 , Tianning Xu  1 , Jinhui Ying  1 , Ran Lu  3 , Huipeng Zhou  4
Affiliations

Two-photon absorption behavior of conjugated oligomers suitable for low colour temperature LEDs

Tianhao Huang et al. RSC Adv. .

Abstract

Light emitting diodes (LEDs) with low colour temperatures (CTs) have been proved to be physiologically-friendly light sources. However, there are few reports on the photophysical properties of luminescent materials with CTs lower than candlelight. Herein, one- and two-photon optical properties of four fluorenone-based conjugated oligomers have been systemically investigated. By using a sum-over-essential states (SOS) approach, we obtained the transition dipole moments and two-photon absorption (TPA) cross sections. The triphenylamine end-capped oligomer exhibits reddish orange luminescence with extremely low colour temperature of 1686 K, which is much lower than that of candlelight. Fluorene-ethylene units serving as π-spacers could weaken the role of electron-donating units and effectively enhance the TPA performance of oligomers. Our results provide an effective way for the design and optimization of universal light-emitting material candidates in optoelectronic devices.

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Conflict of interest statement

There are no conflicts to declare.

Figures

Fig. 1
Fig. 1. The MALDI/TOF MS spectra of compound #1–#4 with 1,8,9-trihydroxyanthracene as a matrix.
Fig. 2
Fig. 2. IR spectra of compound #1–#4.
Fig. 3
Fig. 3. Steady-state absorption spectra of compound #1–#4. The solid lines represent the fitted Gaussian line-shape.
Fig. 4
Fig. 4. CIE coordinates and CTs of #1–#4.
Fig. 5
Fig. 5. (a) Normalized TPF spectra of #1–#4 (5 × 10−4 M); (b) TPF intensity of #1–#4 at different laser intensities over a range of 35–80 μJ; (c) TPF intensity as a function of the square of laser intensity.
Fig. 6
Fig. 6. Multi-energy-level diagrams for compound #1–#4 used to describe the TPA process under the SOS approach.
Fig. 7
Fig. 7. (a) Schematic of the two-colour pump–probe system. BS is beam splitter; M1–M7 are mirrors; C is chopper; L is convex len; S is sample; and D is photodiode detector; (b) two-color pump–probe dynamics for sample solutions at excitation of 410 nm.
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References

    1. Choudhury A. K. R., Principles of Colour and Appearance Measurement, Woodhead Publishing Limited, Cambridge, 2014
    1. Choi K. Shin C. Kim T. Chung H. J. Suk H.-J. Sci. Rep. 2019;9:345. - PMC - PubMed
    1. Mills P. R. Tomkins S. C. Schlangen L. J. M. J. Circadian Rhythms. 2007;5:2. - PMC - PubMed
    1. Jin M. Li X. F. Yan F. Chen W. X. Jiang L. Zhang X. J. Photochem. Photobiol., B. 2021;214:112099. - PubMed
    1. Lin J. Q. Ding X. W. Hong C. Pang Y. L. Chen L. M. Liu Q. W. Zhang X. Xin H. B. Wang X. L. Sci. Rep. 2019;9:7560. - PMC - PubMed