Browsing by Author "Huang, Peishen"
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Item Developments of Furan and Benzodifuran Semiconductors for Organic Photovoltaics(Royal Society of Chemistry, 2015-02-13) Huang, Peishen; Du, Jia; Biewer, Michael C.; Stefan, Mihaela C.; 55039821 (Stefan, MC); Biewer, Michael C.; Stefan, Mihaela C.This review describes the developments of organic photovoltaic materials containing furan or benzo[1,2-b:4,5-b']difuran (BDF) building blocks. Promising power conversion efficiencies above 6% have been achieved in the past two years for the BDF donor-acceptor polymers. Fundamentals of organic photovoltaics are briefly introduced at the beginning of this review. The uniqueness and advantages of BDF building block in semiconducting materials are discussed and compared with benzo[1,2-b:4,5-b']dithiophene analogues.Item Nitrogen Containing Graphene-Like Structures from Pyrolysis of Pyrimidine Polymers for Polymer/graphene Hybrid Field Effect Transistors(Royal Soc Chemistry, 2014-09-02) Gunathilake, Samodha S.; Huang, Peishen; Bhatt, Mahesh P.; Rainbolt, Elizabeth A.; Stefan, Mihaela C.; Biewer, Michael C.; 55039821 (Stefan, MC); Stefan, Mihaela C.; Biewer, Michael C.Nitrogen containing graphene like structures were obtained by the pyrolysis of two pyrimidine polymers at 600 degrees C. Pyrimidine polymers were prepared by the base catalyzed aldol condensation reactions between 2-decyloxy-4,6-dimethylpyrimidine and two aromatic dialdehydes. Pyrolyzed products were shown to have a graphitic structure by Raman spectroscopy, scanning electron microscopy, and powder X-ray diffraction studies. The presence of nitrogen in the graphitic structures was proved by elemental analysis and energy dispersive X-ray analysis experiments. Fluorescence quenching experiments with poly(3-hexylthiophene) (P3HT) showed that the resultant graphitic material can act as an acceptor. These materials were tested in P3HT/graphene hybrid field effect transistors which exhibited higher mobilities and comparable on/off ratios compared to P3HT only devices.Item A Semiconducting Liquid Crystalline Block Copolymer Containing Regioregular Poly-(3-hexylthiophene) and Nematic Poly(n-hexyl Isocyanate) and its Application in Bulk Heterojunction Solar Cells(Royal Soc Chemistry, 2014-08-06) Bhatt, Mahesh P.; Du, Jia; Rainbolt, Elizabeth A.; Pathiranage, Taniya M. S. K.; Huang, Peishen; Reuther, James F.; Novak, Bruce M.; Biewer, Michael C.; Stefan, Mihaela C.; 0000 0000 8413 1147 (Novak, BM); 98037603 (Novak, BM); 55039821 (Stefan, MC); Novak, Bruce M.; Biewer, Michael C.; Stefan, Mihaela C.A liquid crystalline diblock copolymer containing regioregular poly(3-hexylthiophene) (P3HT) and poly-(n-hexyl isocyanate) (PHIC) was synthesized by the combination of Grignard metathesis polymerization (GRIM) and titanium mediated coordination polymerization methods. The poly(3-hexylthiophene)-b-poly(n-hexyl isocyanate) (P3HT-b-PHIC) diblock copolymer used in this study contained ~10 mol% of P3HT and ~90 mol% of PHIC. The diblock copolymer displayed solvatochromism in THF-water and THF-methanol mixtures. The field-effect mobilities of the synthesized block copolymer were measured in bottom gate-bottom contact organic field-effect transistors (OFETs). The surface morphology of the polymer thin film was investigated in the channel region of the OFET devices by tapping mode atomic force microscopy (TMAFM). The diblock copolymer displayed nanostructured morphology in thin film and had good mobility despite the low content of the semiconducting P3HT block. The diblock copolymer was also used as an additive to improve the performance of P3HT/PCBM bulk heterojunction (BHJ) solar cells. Liquid crystalline characteristics of the diblock copolymer were examined by cross-polarizing microscopy and X-ray diffraction.Item Synthesis and characterization of novel semiconducting polymers containing pyrimidine(Royal Soc Chemistry, 2013-02-27) Gunathilake, Samodha S.; Magurudeniya, Harsha D.; Huang, Peishen; Nguyen, Hien; Rainbolt, Elizabeth A.; Stefan, Mihaela C.; Biewer, Michael C.; 55039821 (Stefan, MC); Stefan, Mihaela C.; Biewer, Michael C.The acidic methyl protons of 4,6-dimethylpyrimidines can be easily deprotonated with a base to generate a resonance stabilized carbanion which can be used as a substrate for aldol condensation reactions. A series of novel conjugated polymers were synthesized by the aldol condensation reaction of 2-decyloxy-4,6-dimethylpyrimidine with various aromatic dialdehydes.