Comprehensive Investigation of Efficient Organic Conjugated Materials for Optoelectronics via Material-Synthesis Engineering

Department of Energy Engineering (Energy Engineering)Central to the comprehensive scientific topics for electronic applications such as organic field effect transistors (OFETs), organic photovoltaics (OPVs), and organic light emitting diodes (OLEDs), is a concept of semiconducting conjugated polymers with several fold advantages: light weight, mechanical flexibility and low cost fabrication. Exploited with several fold advantages of easy modulation in optoelectronic properties and synthetic versatility, conjugation based materials have quenched approaching thirsty for renewable energy sources through considerable research efforts. During the period for my combined MS Ph.D course, my main research foci were on synthesis of various and versatile organic conjugated materials for electronic uses with systematic investigation of their structure property relationships. The synthesized oligomeric and polymeric materials were confirmed by diverse analytical tools of NMR, FT IR, GPC, HR MS, EA, and MALDI TOF, after which were characterized for thermophysical, optical, and electrical properties through DSC, TGA, UV Vis, UPS, PL, and CV. In addition to their intrinsic properties, microstructural analysis of morphological and crystalline features was investigated by AFM, TEM, and GIWAXD to figure out the effects on their applications. My dissertation is composed of four sections with a brief overview of conjugated materials for electronics with motivations and directions during my degree. The first and two chapters will cover systematic comparison of heteroaromatic compounds as flanking and counterpart units for diketopyrrolopyrrole containing polymers for OFETs. The third one will discuss the effect of conjugated pathways of benzodithiophene based small molecules for their intrinsic properties and performances on ternary OPVs as third components. The last work will introduce an optimized methodology of Stille polymerization with stepwise heating protocolsclos