A Highly Conjugated p- and n-Type Polythiophenoazomethine: Synthesis, Spectroscopic, and Electrochemical Investigation

Macromolecules, 2007, 40 (6), pp 1792–1795

An Ambipolar Peryleneamidine Monoimide-Fused Polythiophene with Narrow Band Gap

The donor−acceptor system can be electropolymerized to generate a functionalized polythiophene with a band gap of 0.9 eV and with ambipolar characteristics showing high electroactivity in both the p- and the n-doping process.

Org. Lett., 2007, 9 (11), pp 2171–2174

Synthesis and Characterization of Electron-Deficient and Highly Soluble (Bis)Indenofluorene Building Blocks for n-Type Semiconducting Polymers

These derivatives exhibit optical band gaps of 1.83 to 2.44 eV and low LUMO energies of −3.24 to −4.30 eV, representing a promising new building block class for n-type polymeric electronic materials.

Org. Lett., 2008, 10 (7), pp 1385–1388

Synthesis and Absorption Spectra of n-Type Conjugated Polymers Based on Perylene Diimide

The onset reduction (n-doping) potentials of PDIV and PDITh are at -0.62 V and -0.66 V versus Ag/Ag⁺ respectively, which correspond to the electron affinities (EAs) of 4.09 eV for PDIV and 4.05 eV for PDITh.

Macromolecular Rapid Communications Volume 29 Issue 17, Pages 1444 - 1448

Low-Bandgap Pyrazine Polymers: Ladder-Type Connectivity by Intramolecular S···N(sp2) Interactions and Hydrogen Bonds

Macromolecules, 2009, 42 (7), pp 2309–2312

Design, Synthesis, and Characterization of Ladder-Type Molecules and Polymers. Air-Stable, Solution-Processable n-Channel and Ambipolar Semiconductors

The onset LUMO energy for carrier electron stabilization is estimated as −4.0 to −4.1 eV, indicating an overpotential of 0.9−1.0 eV.

J. Am. Chem. Soc., 2009, 131 (15), pp 5586–5608

Diketopyrrolopyrrole-Containing Polyfluorenes: Facile Method To Tune Emission Color and Improve Electron Affinity

A series of novel diketopyrrolopyrrole (DPP)-containing polyfluorenes, coded as PF-DPP01-50, were synthesized through palladium-catalyzed Suzuki polycondensation with different feed ratios between fluorene dibromide and DPP dibromide. Their chemical structures and compositions were verified by ¹H NMR and elemental analysis. DSC and TGA results show that they have good to excellent thermal stabilities. Absorption and photoluminescence (PL) properties of PF-DPP01-50, determined in both CHCl₃ solutions and thin films, exhibit regular changes with increasing of DPP contents in copolymers, with absolute PL efficiencies being in the range 13.8-26.9%. Electroluminescence (EL) properties of all the copolymers were investigated with device configurations of ITO/PEDOT/copolymer/Ba/Al and ITO/PEDOT/copolymer/Al. A very low content of DPP units (1%) is needed to achieve full energy transfer from fluorene segments to DPP units; hence, exclusive emission of the latter occurs. EL colors of these copolymers vary from orange to red, corresponding to CIE coordinates from (0.52, 0.46) to (0.62, 0.37). The best performance was achieved by orange-emitting PF-DPP01 in device configuration of ITO/PEDOT/copolymer/Ba/Al, with maximum EQE of 0.45% and maximum brightness of 520 cd/m². Devices with configuration of ITO/PEDOT/copolymer/Al prove that DPP units can effectively improve the electron affinity of these copolymers. One of these devices (ITO/PEDOT/PF-DPP25/Al) can realize maximum EQE of 0.14% and maximum brightness of 127 cd/m². Therefore, color-tuning (red-shift) and improvement of electron affinity can be achieved at the same time through incorporation of DPP units.

Macromolecules, 39 (24), 8347 -8355, 2006.