Polymer solar cells have been spotlighted due to their potential for low-cost manufacturing but their efficiency is still less than required for commercial application as lightweight/flexible modules. Forming a dipole layer at the electron-collecting interface has been suggested as one of the more attractive approaches for efficiency enhancement. However, only a few dipole layer material types have been reported so far, including only one non-ionic (charge neutral) polymer. Here we show that a further neutral polymer, namely poly(2-ethyl-2-oxazoline) (PEOz) can be successfully used as a dipole layer. Inclusion of a PEOz layer, in particular with a nanodot morphology, increases the effective work function at the electron-collecting interface within inverted solar cells and thermal annealing of PEOz layer leads to a state-of-the-art 10.74% efficiency for single-stack bulk heterojunction blend structures comprising poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-alt-3-fluorothieno[3,4-b]thiophene-2-carboxylate] as donor and [6,6]-phenyl-C71-butyric acid methyl ester as acceptor.

Nature Communications 6, Article number: 8929 doi:10.1038/ncomms9929
Received 27 April 2015 Accepted 19 October 2015 Published 14 December 2015

http://www.nature.com/ncomms/2015/151214/ncomms9929/full/ncomms9929.html

聚合物太阳能电池因其较低的加工成本而受到关注，不过这类电池的效率还无法满足商业应用。在电子收集界面上形成一层偶极层是提高电池效率的有效方法。不过，迄今为止只有很少的偶极层材料被报道过，其中包括一些电中性聚合物。Nam等人合成了一种电中性聚合物—聚（2-乙烯基-2-恶唑啉）（PEOz），这种材料可以成功的被用作偶极层。在电子收集界面间插入 PEOz 层（特别是以纳米点的形式）后，经过退火处理，倒装太阳能电池器件的最佳能量转化效率可以达到 10.74% 。（新材料在线）