Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, Singapore.
ACS Appl Mater Interfaces. 2009 Jul;1(7):1467-73. doi: 10.1021/am900144b.
We report herein a detailed study of the thermal and hole-transport properties of poly[2,7-(9,9-dihexylfluorene)-alt-bithiophene] (F6T2) and its photovoltaic performance in a bulk-heterojunction (BHJ) solar cell. This crystalline polymer has a high weight-average molecular weight (M(w) = 52 400) with a polydispersity index of 1.99. With a band gap of 2.36 eV, F6T2 exhibits strong absorption in the 300-500 nm region. BHJ solar cells blending F6T2 with [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) (1:3 weight ratio) as the active layer present a high open-circuit voltage (V(oc) approximately 0.9 V) and a promising power conversion efficiency of 2.4% under simulated solar light AM1.5G (100 mW/cm(2)). Furthermore, F6T2 shows sufficient hole mobility [ca. 8.4 x 10(-5) cm(2)/(V s) at 310 K and 2.5 x 10(5) V/cm applied electric field] by a time-of-flight transient photocurrent technique, allowing efficient charge extraction and a good fill factor for solar cell application. Nanoscale phase separation was observed in F6T2/PCBM films with a surface roughness lower than 60 nm.
我们在此报告了聚[2,7-(9,9-二己基芴)-交替-双噻吩]（F6T2）的热和空穴传输性能及其在体异质结（BHJ）太阳能电池中的光伏性能的详细研究。这种结晶聚合物具有高分子量（M(w)=52400）和高的分子量分布指数（1.99）。F6T2 的带隙为 2.36eV，在 300-500nm 区域具有很强的吸收。以 F6T2 和[6,6]-苯基-C（61）-丁酸甲酯（PCBM）（1:3 重量比）为活性层的 BHJ 太阳能电池具有高开路电压（V(oc)约为 0.9V）和在模拟太阳光 AM1.5G（100mW/cm(2)）下具有 2.4%的有前途的功率转换效率。此外，通过飞行时间瞬态光电流技术，F6T2 显示出足够的空穴迁移率[约 8.4×10(-5)cm(2)/(V s)在 310K 和 2.5×10(5)V/cm 施加电场]，允许有效的电荷提取和良好的填充因子太阳能电池的应用。在 F6T2/PCBM 薄膜中观察到纳米级相分离，表面粗糙度低于 60nm。
