Novel semiconducting polymers: Synthesis, characterization, and their application in organic electronics

Conjugated polymers have attracted considerable attention as semiconducting materials in recent years due to their versatile electronic and optoelectronic applications. The main promise of conjugated polymers is not just attaining or exceeding the level of performance of silicon technologies but also producing electronic devices at a lower cost and enabling completely new device functionalities such as light weight, large surface area, mechanical flexibility, and optical transparency. Due to their broad potential, conjugated polymers have been incorporated in the wide range of applications, including polymer light-emitting diodes (LEDs), organic field-effect transistors (OFETs), and polymer solar cells (PSCs).;Chapter 1 provides general information on conjugated polymers utilized in polymer light-emitting diodes (LEDs), polymer solar cells (PSCs) and organic field effect transistors (OFETs). It also includes brief description and schematic diagrams for each device configuration.;Chapter 2 describes the synthesis, characterization and electronic properties of a novel symmetrical sulfone-substituted polyphenylene vinylene (SO 2EH-PPV) for applications in light-emitting devices. The sulfonyl functional group was directly attached to the polymer's backbone to increase the electron affinities of the polymer. The polymer was incorporated into a single layer PLED devices with the configuration of (ITO/ PEDOT:PSS/SO2EH-PPV polymer/Al).;Chapter 3 focuses on the synthesis and color tuning of novel poly (fluorenevinylene-co-sulfonylphenylenevinylene) based copolymers for application in light-emitting diodes. New electroluminescent Poly(fluorenevinylene)-co-(sulfonylphenylenevinylene) random copolymers with different monomer feed ratios (PFV-SO2EH 10 and PFV-SO2EH 50) were synthesized via palladium-catalyzed Stille coupling reaction. Single layer stable PLED devices with the configuration of (ITO/PEDOT:PSS/PFV-SO 2EH 10 & PFV-SO2EH 50 polymer/Al) were fabricated exhibiting a light emission ranging from bright yellow to orange/red color.;Chapter 4 describes the synthesis and molecular energy level control of novel fluorinated polythienothiophene-co-dialkylthio benzodithiophene low band gap semiconducting polymers, SEH-PBDTTT-F and SO-PBDTTT-F for application in polymer solar cells. The objective was to effectively tune the energy levels (lower the HOMO and LUMO levels) of the resulting polymers by replacing the alkoxy with thioalkoxy units in BDT moiety and effectively enhance the open-circuit voltage (Voc), as one of the key parameters in determining the PCE of solar cells.