Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan.
ACS Appl Mater Interfaces. 2012 Nov;4(11):6289-94. doi: 10.1021/am301905m. Epub 2012 Oct 25.
Two molecular disks 1 and 2 composed of a central pyrene core, four oligothiopenes, and peripheral alkyl chains were synthesized and characterized with respect to optical and redox properties in solution and in solid films. It was found that the lowest unoccupied molecular orbital (LUMO) energy levels of 1 and 2 were ideal for achieving efficient electron transfer to fullerene derivatives PC₆₀BM and PC₇₀BM, and that 1 and 2 can function as electron donor components in solution-processed bulk-heterojunction (BHJ) solar cells. Disk-shaped molecules 1 and 2 organized ordered structures through intermolecular π-π interactions as monitored by temperature-controlled polarized optical microscope (TPOM), differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD). Solution-processed BHJ solar cells using 1 or 2 as electron donor materials and fullerene derivatives as acceptor materials were fabricated and investigated. The oligothiophene lengths were reflected in the performance characteristics of solar cell devices fabricated using disk-shaped donors 1 and 2. Power conversion efficiency (PCE) of 2.6% was achieved for small-molecule BHJ solar cells containing self-organized crystals of 2 in the active layer under one sun condition.
两个由中央芘核心、四个寡聚噻吩和外围烷基链组成的分子盘 1 和 2 已被合成并对其在溶液中和固体薄膜中的光学和氧化还原性质进行了表征。结果发现，1 和 2 的最低未占分子轨道（LUMO）能级非常适合实现与富勒烯衍生物 PC60BM 和 PC70BM 的有效电子转移，并且 1 和 2 可以作为溶液处理的体异质结（BHJ）太阳能电池中的电子给体组件。盘状分子 1 和 2 通过分子间π-π相互作用形成有序结构，这可通过温度控制的偏振光显微镜（TPOM）、差示扫描量热法（DSC）和粉末 X 射线衍射（XRD）监测到。使用 1 或 2 作为电子给体材料和富勒烯衍生物作为受体材料制备和研究了溶液处理的 BHJ 太阳能电池。使用盘状给体 1 和 2 制备的太阳能电池器件的性能特征反映了寡聚噻吩的长度。在阳光条件下，含有 2 自组装晶体的活性层的小分子 BHJ 太阳能电池的功率转换效率（PCE）达到 2.6%。
