Performance enhancement of poly(N-vinycarbazole) with Covalently Bonded C60 for photovoltaic application

The performance of a photovoltaic device composed of poly(N-vinylcarbazole) with Covalently Bonded C₆₀ (PVK- C₆₀) exhibits a significant improvement compared with its corresponding simple poly(N-vinylcarbazole) and C₆₀ blend under the same condition. The open circuit voltage (Voc) is increased from 0.25V for their blend to more than 1V for PVK-C₆₀ copolymer. In PVK-C₆₀ copolymer, the carbazole block acts as donor and covalently attached fullerene (C₆₀) acts as acceptor. The absorption edge of PVK-C₆₀ extends through the entire visible spectrum, while their blend has very weak absorption in this range. PL spectrum shows that there is more obvious spectrum quenching for PVK-C₆₀ copolymer than their blend which implies well-mixed states of donor (carbazole) and acceptor (C₆₀) in PVK-C₆₀ copolymer.