Architecture of Conjugated Donor-Acceptor (D-A)-Type Polymer Films with Cross-Linked Structures

A series of new donor-acceptor (D-A)-type semiconducting conjugated polymers (SCPs), which can form cross-linked structural and supra molecular assembly films by hydrogen-bonding, is successfully synthesized. The microstructures of supramolecular assembly films are further investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and variable-temperature Fourier transform infrared (FT-IR) absorption spectra. As electronic transmission (ET) materials, the SCPs demonstrate superior properties by means of fabricating electron-only devices with the configuration of ITO/ET (SCPs)/Ca/Al. According to space-charge-limited current (SCLC) measurements, fluorine-containing SCPs exhibit much smaller threshold voltages and much higher electron mobilities than Alq(3). Meanwhile, a significant enhancement for their luminescence properties is verified by the photoluminescence (PL) and electroluminescent (EL) spectra of cross-linked-type SCPs, compared to non-cross-linked-type SCPs. The fabricated polymer light-emitting diodes (PLEDs) with the configuration of ITO/PEDOT:PSS/EML (SCPs)/BCP/LiF/Al are able to emit the color from green to red with moderately low turn-on voltages. These results suggested that cross-linked D-A-type SCP can become a potential candidate as a kind of multifunctional materials applied in the field of optoelectronic devices.