Dr. Vishnumurthy K A

Design and synthesis of conjugated polymers

Polymeric solar cells (PSCs) have attracted considerable attention in recent years due to their potential for low cost, lightweight, and good compatibility with the roll-to-roll process for making flexible large area devices. Amongst various type of polymer solar cells, bulk-heterojunction-type solar cells use a phase separated blend of organic electron donor and acceptor components, where the conjugated polymer is often used as the donor and the modified fullerene derivative is used as the acceptor. In this context our research mainly focuses on the synthesis of low band gap donor-acceptor type polymeric materials. Further the tuning of lowest unoccupied molecular orbital (LUMO) and Highest occupied molecular orbital (HOMO) will be done by changing the molecular architecture in the backbone and side chain of the polymer.   To optimize the material properties, conjugated polymers with alternating electron-rich and -deficient units along their backbone have been extensively developed and absorption spectra and band gap of the were tuned by controlling the intramolecular charge transfer (ICT) from the donors to the acceptors.