文摘
Two new donor鈥揳cceptor alternating wide band gap copolymers, PTTDBC-PhQC8 and PTTDBC-BTC12, based on an electron-rich tetrathienodibenzocarbazole (TTDBC) donor have been designed and synthesized, wherein two additional thienyl rings are fused into a 2,7-dithienylcarbazole skeleton to reinforce the structural coplanarity and rigidity of polymers. The quinoid thiophene in TTDBC can endow not only a wide optical band gap (鈭?.9 eV) but also a deep HOMO (鈭?.3 eV) for the resulting polymers. The conventional configuration solar cells based on PTTDBC-BTC12 exhibit a large Voc of 0.91 V and a power conversion efficiency of 4.30% (with a Jsc of 9.27 mA cm鈥? and a FF of 0.51), while a slightly higher PCE of 4.50% can be achieved for the inverted structure devices. We believe that these wide band gap polymers have potential to be used for tandem cell applications.