Achieving Tuneable, Asymmetrical, Pyrene-Based Luminogens for Latent Fingerprint Extraction and Flexible Light Source Fabrication

The application of organic luminescent materials is becoming diversified in the fields of display technology, imaging, chemosensors and information encryption, but improving luminescent efficiency and color purity remains a challenge. Herein, new insight for fine tuning asymmetrical pyrene-based luminogens is discussed by constructing Donor-π-Acceptor (D-π-A) type molecules along the short axis at the pyrene core. Further experiments and calculations demonstrate the possibility of dual emission with near-white color emitting and narrow full-width half maximum (FWHM) materials (∼12 nm for 7- tert -butyl-1-phenyl-3-carbazolylpyrene ( CzPy) in film) by regulating electron-donating/withdrawing groups. Experimental results prove that the luminescent efficiency shows strong competitiveness in the solid state (14.3% for CzPy ) and in the pyrene luminogen-doped amorphous polymer (29.5% for 7- tert -butyl-1-phenyl-3- N,N -diphenylaminopyrene ( DPaPy )). The narrow FWHM dedicated to improving color purity and reasonable luminescent efficiency were achieved. Furthermore, these findings not only enabled development of a new application of latent fingerprint extraction with high resolution but also provided an innovative strategy for the fabrication of flexible light source displays.