State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology , 381 Wushan Road, Guangzhou 510640, China.
ACS Appl Mater Interfaces. 2017 Mar 1;9(8):7131-7138. doi: 10.1021/acsami.6b15241. Epub 2017 Feb 17.
A porphyrin-based molecule DPPEZnP-BzTBO with bulky benzothiophene groups was designed and synthesized as an electron donor material for bulk heterojunction (BHJ) solar cells. The optimized devices under thermal annealing (TA) and then chloroform solvent vapor anneanling (SVA) for 80 s exhibited an outstanding power conversion efficiencie (PCE) of 9.08%. Contrasted with the smaller thienyl substituted analogues we reported previously, DPPEZnP-BzTBO-based BHJ solar cells exhibited a higher open circuit voltage due to the lower highest occupied molecular orbital energy level. The TA post-treatment of the active layers induced the formation of more crystallized components, and the subsequent SVA provided a driving force for the domain growth, resulting in more obvious phase segregation between the donor and the acceptor in nanoscale. Furthermore, the PCEs kept above 95% upon the further SVA treatment within the time range of 60 to 95 s probably because the bulky benzothiophene groups retard the too quick change of crystallinity, providing a wide processing window for the reproducible device fabrication.
一种基于卟啉的分子 DPPEZnP-BzTBO 带有较大的苯并噻吩基团，被设计并合成作为体异质结（BHJ）太阳能电池的电子给体材料。经热退火（TA）和然后氯仿溶剂蒸汽退火（SVA）80 秒优化后的器件表现出 9.08%的出色功率转换效率（PCE）。与我们之前报道的较小的噻吩取代类似物相比，基于 DPPEZnP-BzTBO 的 BHJ 太阳能电池由于最高占据分子轨道能级较低，表现出更高的开路电压。活性层的 TA 后处理诱导了更结晶成分的形成，随后的 SVA 为畴生长提供了驱动力，导致供体和受体在纳米尺度上更明显的相分离。此外，在 60 至 95 秒的进一步 SVA 处理时间范围内，PCE 保持在 95%以上，这可能是因为较大的苯并噻吩基团阻碍了结晶度的过快变化，为可重复器件制造提供了更宽的加工窗口。
