Work

Distinct mechanochromic and piezochromic behaviors of thermally activated delayed fluorescence 4CzTPN crystal

Year: 2025

Type: article

Abstract: Incorporating mechano-luminescence into thermally activated delayed fluorescence (TADF) molecules represents a promising strategy for developing multifunctional mechanoluminescent materials. However, the controllable utilization of the versatile properties inherent in TADF molecules remains challenging due to the inherent difficulties in system design. Herein, we investigate the pressure modulation of the photophysical properties of 2,3,5,6-tetrakis(carbazol-9-yl)-1,4-dicyanobenzene (4CzTPN), a representative TADF emitter, through in situ high-pressure photoluminescence (PL), time-resolved PL, UV-visible spectra and infrared spectroscopy. The different mechanisms of a blue shift by grinding crystals and of a red shift under hydrostatic pressure are fully investigated. High-pressure time-resolved PL measurements show that the short fluorescence lifetime decreases and the lifetime of delayed fluorescence disappears beyond 3.0 GPa. Infrared spectra indicate the pattern of relative intensity for the infrared absorption peak of ν(C-H) transform significantly when the pressure is greater than 3.0 GPa, which would be the cause of the disappearance of delayed fluorescence. This study enriches the insights into mechanochromic and multifunctional materials.

Source: Scientific Reports

DOI: 10.1038/s41598-025-20002-z

Authors: Yarong Gu, Long Li, Min Wu, Kai Wang

Institution: Liaocheng University

Language: English

Topic: Luminescence and Fluorescent Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,690

Funders: National Natural Science Foundation of China, Natural Science Foundation of Shandong Province, Applied Basic Research Project of Shanxi Province, China