DOUBLE CABLE POLYTHIOPHENE DONOR – NON-FULLERENE ACCEPTORS POLYMERS AND THEIR HYBRIDS FOR LIGHT HARVESTING AND ENERGY CONVERSION TECHNOLOGIES
Date: February 26, 2026 Time: 11:00 AM Location: Dean’s Smart Lab (4th Floor)
Student(s): Faseeh Akbar (22130024)
The world’s energy and environmental problems are largely caused by our heavy use of fossil fuels like coal, oil and gas. These fuels store energy originally captured from sunlight by plants and microorganisms millions of years ago through photosynthesis. Burning them releases harmful gases which lead to global warming, air pollution and other environmental issues. To protect the planet, we need to transition to renewable energy sources such as solar, wind and hydropower. Scientists are developing ways to use sunlight in two main ways, i.e., generating electricity with solar cells and storing energy chemically through artificial photosynthesis. At the core of these technologies are photoactive materials which respond to light. These materials can be organic, inorganic or a combination of both. Among them, organic semiconducting polymers (OSPs) are promising because they are lightweight, easy to process into thin films and their light-absorbing properties can be tuned by changing their molecular structure. However, organic semiconductors face a challenge of high binding energy of electrons. In organic semiconductors light absorbance generates pairs of positive (holes) and negative (electrons) charges called excitons, which recombine quickly, limiting their use in electricity generation or chemical reactions. To overcome this, a wide explored strategy combines an electron donor (D) with an electron acceptor (A) that displays relatively higher electron affinity. The acceptor helps separate the charges, improving light-to-energy conversion efficiency. D-A systems can be created either by physically mixing the materials or by chemically bonding them into a single molecule. Covalently bonded D-A systems perform better because the D and A are closer spatially which enhance electronic interaction and charge separation that eventually translates into energy conversion. Among OSPs, linear organic polymers allow precise control over structure and light absorption. A special type named double cable polymers (DCPs) consists of linear OSPs bearing covalently conjugated electron acceptor moieties as side chains. DCPs, because of their D-A covalent construct, show superior light harvesting and energy conversion abilities compared to their individual components and physical blends. Despite their interesting properties, DCPs have been less explored in photocatalysis.
This seminar will display our efforts in developing DCPs that are synthesizing through sidechain engineering of polythiophene (PTh) electron donor and subsequent covalent conjugation to non-fullerene acceptors (NFAs). The produced DCPs are characterized to assess their ability to generate electrical current and their performance as photoactive materials in artificial photosynthesis. The properties of DCPs are compared with the individual D, A species or physical (D+A) blends. The discussion menu also includes the insights into the differences in characteristics of random and block copolymer, and the impact of interfacing DCPs with functional additives such as reduced graphene oxide and plasmonic Au nanoparticles. Specifically, we will share insights into PTh-PDI-DCP, a double cable polythiophene – perylene polymer and its hybrids. In short, our work contributes towards expanding the design space of organic photoactive materials and their functional hybrids.
26
Feb
Date: February 26, 2026
Time: 11:00 AM
Location: Dean’s Smart Lab (4th Floor)
Student(s): Faseeh Akbar (22130024)