Review—Conjugated Polymer Photovoltaic Materials: Performance and Applications of Organic Semiconductors in Photovoltaics

Silicon based inorganic semiconductors were preferred to make solar cells for a long time until scalability and actual commercialization of inorganic photovoltaics at reasonable costs became a problem. The coming of organic semiconductor based technologies proved beneficial as the fabrication of unique optoelectronic devices were achieved at relatively lower costs and new device functionalities like improved optical transparency, enhanced mechanical flexibilities became a possibility. The usage of organic polymers as electron donors and acceptors multiplied the benefits of synthesizing organic photovoltaics by several folds, although only a power conversion efficiency of over 18% has been achieved so far. Putting together various inferences made through the years, this review aims at establishing a comprehensive understanding of organic photovoltaics and the science of bulk heterojunction solar cells. The need for low-bandgap photoactive materials and the different ways to synthesize them has been elaborated and a detailed review of the various donor and acceptor semiconducting polymers has been done. Towards the end, this paper provides a comprehension of the specific strategies that might improve the industrial scalability of organic photovoltaics, following which the challenges and the future of organic photovoltaics-based research have also been highlighted.