Polyselenopheno[3,4-b]selenophene for Highly Efficient Bulk Heterojunction Solar Cells

Herein we describe the synthesis of a new series of copolymers (PSeB x ) containing selenopheno[3,4- b ]selenophene and benzodiselenophene, which exhibited a high power conversion efficiency (PCE) of 6.87% in a bulk heterojunction (BHJ) solar cell device (PSeB2/PC 71 BM). In comparison with its thiophene analogue, PTB9, the new polyselenopheno[3,4- b ]selenophene- co -benzodiselenophene (PSeB2) showed a lower band gap and improved charge carrier mobility as high as 1.35 × 10 –3 cm 2 V –1 s –1 .