The Design And Optoelectronic Properties Of Fluorene-based Materials With The Modulation Of Functional Groups

In the first work, we design a series of donor-acceptor type solution-processable anthraquinone/fluorene hybrid bipolar fluorescent materials using the ladder-type oligo(p-phenylene)s and anthraquinone as hole and electron transport units, respectively. The planar and rigid structure of ladder-type oligo(p-phenylene)s would facilitate π-electron delocalization to increase photoluminescence efficiency and enhance the photochemical and thermal stability. With the introduction of anthraquinone moiety, the electron injection barrier of ladder-type oligo(p-phenylene)s can be efficiencily mediated to improve its electron injection/transportation and balance of the carrier transport in the material, further enhancing the performance of the device. These materials have good thermal stability and well-matched bipolar charge-transport characteristics, and the OLED devices using them as the emitting layer exhibit excellent colour purity and operational stability.In another work, we design a series of photochromophore based on 1,2-bis(2-methylthiophen-3-yl)cyclopent-1-ene, from the two respects of introducing aromatic substituents and topological structure, to enhance the molecular rigidity and conjugation, further improving the thermal stability of diarylethenes. Two novel thermally stable diarylethenes are synthesized, either by adopting the ladder-type oligo(p-phenylene)s as the side substituent or by the Friedel crafts cyclization with 9,9’-diphenyl-9H,9’H-[2,2’-bifluorene]-9,9’-diol. Their photochromic properties have been premilarily investigated by UV-Vis absorption spectra. Furthermore, application of the photochromic compound in organic memory diode has been demonstrated, with fatanstic light switching between different storage-modes.