Synthesis of thiophene, selenophene and thiophene-s-dioxide based organic semiconductors for organic electronics

Abstract

Solid materials having electrical conductivity greater than insulators but less than metals are semiconductors. Carbon-based materials that exhibit semiconductor properties are known as organic semiconductors (OSCs). These materials hold promise for flexible, lightweight, inexpensive and easy to fabricate devices. Due to these advantages, OSCs have gained tremendous interest in recent decades for their use in solar cells, thin film transistors and light emitting diodes. OSCs can be broadly classified in two categories: conjugated polymers (CPs) and small molecules.

(1) CPs: Organic macromolecules which have a backbone chain of alternating double/triple- and single-Bonds are known as CP. Application and device fabrication is dictated by the Energy gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Therefore it is a vital parameter for CPs. Here, the synthesis a narrow bandgap conjugated polymer- Poly(3- alkoxy selenophene), inspired from poly(3-alkoxythiophene), will be discussed.

Li ion batteries may catch fire due to the conventionally used cathode material, LiCoOn. We have formed a mixture, comprised of poly(3-alkoxy thiophene) and Li salt, as an alternative material for the cathode in Li ion batteries.

(2) Small molecules: Small molecules were synthesized based on the electron deficient moiety of Benzodithiophene-S,S-tetraoxide (BDTT) via Cu catalyzed C-H activated direct arylation. Reaction conditions were optimized for various parameters like catalysts, ligands and base. Also, the optoelectronic properties of these molecules were studied.