Improving photovoltaic performance of the linear benzothienoindole-terminated molecules by tuning molecular framework and substituted position of terminals

A novel type of the benzo[4,5]thieno[2,3- b ]indole (BTI)-terminated small molecules (SMs) with a D′(A-D) 2 null framework were synthesized and characterized, i.e. BDT(DPP- 9 -BTI) 2 , BDT(DPP- 8 -BTI) 2 null and 2T(DPP- 8 -BTI) 2 , in which the central donor (D′) units are benzodithiene (BDT) and dithiophene (2T), the armed acceptor (A) unit is dithienyl-diketopyrrolopyrrole (DPP), and the terminated donor (D) unit is BTI with different...