Jump to main content
Jump to site search

Issue 40, 2019
Previous Article Next Article

Aggregation-induced emission triggered by the radiative-transition-switch of a cyclometallated Pt(ii) complex

Author affiliations

Abstract

Aggregation-induced emission (AIE) has been a vitally important research topic on luminescent materials. AIE-active emitters are usually developed based on the mechanisms of restriction of intramolecular rotation (RIR) or restriction of intramolecular vibration (RIV). Herein, we report a simple phosphorescent Pt(II) complex DPA-Pt that shows impressive AIE behavior mainly because of a new mechanism. In THF/H2O mixture solutions with the water fraction (fw) increasing from 0 to 60%, DPA-Pt shows rather weak phosphorescence with the intensities slowly increasing and the emission profiles remaining almost unchanged. Once the fw reached 70–90%, the emissions are greatly enhanced with new peaks appearing and shifting to longer wavelengths. The emission of the vacuum-deposited DPA-Pt neat film is further red-shifted to the deep-red/near-infrared (NIR) region with the photoluminescence quantum yield (PLQY) markedly increased to 0.33. The experimental and theoretical results indicate that the significant enhancement and red-shift of emissions from in dilute solution to aggregation are mainly triggered by the radiative-transition-switch (RTS) from the intra-ligand charge transfer (ILCT) to the metal–metal-to-ligand charge transfer (MMLCT), indicating that RTS is a new mechanism behind this AIE phenomenon. The non-doped OLED based on DPA-Pt exhibits deep-red/NIR emission with a peak external quantum efficiency of 9.8%, which is not only higher than that of the 6 wt% doped device based on DPA-Pt, but also much higher than those reported for the state-of-the-art non-doped deep-red/NIR OLEDs based on other AIE-active emitters.

Graphical abstract: Aggregation-induced emission triggered by the radiative-transition-switch of a cyclometallated Pt(ii) complex

Back to tab navigation

Supplementary files

Publication details

The article was received on 16 Jul 2019, accepted on 11 Sep 2019 and first published on 12 Sep 2019


Article type: Paper
DOI: 10.1039/C9TC03838H
J. Mater. Chem. C, 2019,7, 12552-12559

  •   Request permissions

    Aggregation-induced emission triggered by the radiative-transition-switch of a cyclometallated Pt(II) complex

    Y. Sun, X. Yang, B. Liu, H. Guo, G. Zhou, W. Ma and Z. Wu, J. Mater. Chem. C, 2019, 7, 12552
    DOI: 10.1039/C9TC03838H

Search articles by author

Spotlight

Advertisements