合成了含三异丙硅乙炔基(TIPS)和烷氧基(OEH)不同侧链的苯并[1,2-b∶4,5-b']二噻吩(BDT)基窄带隙交替共聚物: PBDT-TIPS-DTBT和PBDT-OEH-DTBT.聚合物吸收300～730 nm范围太阳光,光学带宽(Eoptg)约1.7 eV.当侧链由OEH变为TIPS时,最高占据分子轨道(HOMO)降至-5.35 eV,比PBDT-OEH-DTBT降低了0.19 eV.以PBDT-TIPS-DTBT作给体、PC61BM作受体制备了本体异质结(BHJ)聚合物太阳能电池,在AM1.5,100 mW·cm-2光照条件下,活性层给受体质量比为1∶1时,能量转化效率(PCE)达2.40％,开路电压(VOC)、短路电流密度(JSC)和填充因子(FF)分别为0.86 V、4.79 mA·cm-2和58.37％.%Two low band gap alternating benzo[1,2-b∶4,5-b']dithiophene (BDT) based copolymers containing different side chains triisopropylethynyl ( TIPS) and 2-ethylhexyloxy ( OEH) , namely, PBDT-TIPS-DTBT and PBDT-OEH-DTBT, were synthesized. Both copolymers showed the broad absorption spectra in a range of 300～730 nm, with the optical band gap ( Eoptg ) of c.a. 1.7 eV. When the side chain of polymer backbone was changed from OEH to TIPS, the highest occupied molecular orbital ( HOMO ) energy level decreased from -5.16 eV to -5.35 eV. Bulk-heterojunction polymer solar cells ( PSCs) were fabricated, based on PBDT-TIPS-DTBT as donor, PC61 BM as acceptor ( D/A weight ratio 1∶1) and Ca/Al as negative electrode. Under the illumination of AM1.5, 100 mW·cm-2 , the PSCs showed the best PCE of 2.40％, with VOC of 0.86 V, JSC of 4.79 mA·cm-2 , FF of 58.37％.
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