Development of new semiconducting polymers for high performance organic solar cells

A series of novel semiconducting polymers based on thieno[3,4- b]thiophene has been developed for photovoltaic application. Through controlling the structural and electronic properties of the polymer, their photovoltaic effects in bulk hetero-junction solar cell can be optimized. Power conversion efficiencies of over 7% have been achieved from polymers with alternating thieno[3,4-b]]thiophene and benzodithiophene unit, which are among the highest values reported for polymer solar cell system. The polymer backbone provides an encouraging platform for search of new polymers with improved solar cell performance for practical application.