Frequency-Upconverted Stimulated Emission by Up to Six-Photon Excitation from Highly Extended Spiro-Fused Ladder-Type Oligo(p-phenylene)s

Yi Jiang; King Fai Li; Kun Gao; He Lin; Hoi Lam Tam; Yuan-Yuan Liu; Yu Shu; Ka-Leung Wong; Wen-Yong Lai; Kok Wai Cheah; Wei Huang

doi:10.1002/anie.202100542

Frequency-Upconverted Stimulated Emission by Up to Six-Photon Excitation from Highly Extended Spiro-Fused Ladder-Type Oligo(p-phenylene)s

Angew Chem Int Ed Engl. 2021 Apr 26;60(18):10007-10015. doi: 10.1002/anie.202100542. Epub 2021 Apr 1.

Authors

Yi Jiang^{1

2}, King Fai Li², Kun Gao¹, He Lin¹, Hoi Lam Tam², Yuan-Yuan Liu¹, Yu Shu², Ka-Leung Wong³, Wen-Yong Lai^{1

4}, Kok Wai Cheah², Wei Huang^{1

4}

Affiliations

¹ Key Laboratory for Organic Electronics and Information Displays (KLOEID) & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
² Department of Physics and Institute of Advanced Materials, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China.
³ Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China.
⁴ Frontiers Science Center for Flexible Electronics (FSCFE), MIIT Key Laboratory of Flexible Electronics (KLoFE), Shaanxi Key Laboratory of Flexible Electronics, Xi'an Key Laboratory of Flexible Electronics, Xi'an Key Laboratory of Biomedical Materials & Engineering, Xi'an Institute of Flexible Electronics, Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, China.

PMID: 33476095
DOI: 10.1002/anie.202100542

Abstract

Frequency-upconverted fluorescence and stimulated emission induced by multiphoton absorption (MPA) have attracted much interest. As compared with low-order MPA processes, the construction of high-order MPA processes is highly desirable and rather attractive, yet remains a formidable challenge due to its inherent low transition probability. We report the observation of the first experimental frequency-upconverted fluorescence and stimulated emission by simultaneous six-photon excitation in an organic molecular system. The well-designed organic conjugated system based on cross-shaped spiro-fused ladder-type oligo(p-phenylene)s (SpL-z, z=1-3) manifests reasonably high MPA cross-sections and brilliant luminescence emission simultaneously. The six-photon absorption cross-section of SpL-3 with an extended π-conjugation was evaluated as 8.67×10^-169 cm¹² s⁵ photon^-5 . Exceptionally efficient 2- to 6-photon excited stimulated emission was achieved under near-infrared laser excitation.

Keywords: MPA cross-section; frequency-upconverted stimulated emission; multiphoton absorption (MPA); oligo(p-phenylene)s; spiro-fused molecules.

Abstract

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