Peet J, Kim J Y, Coates N E, Ma W L, Moses D, Heeger A J, Bazan G C
Center for Polymers and Organic Solids, University of California at Santa Barbara, Santa Barbara, California 93106, USA.
Nat Mater. 2007 Jul;6(7):497-500. doi: 10.1038/nmat1928. Epub 2007 May 27.
High charge-separation efficiency combined with the reduced fabrication costs associated with solution processing and the potential for implementation on flexible substrates make 'plastic' solar cells a compelling option for tomorrow's photovoltaics. Attempts to control the donor/acceptor morphology in bulk heterojunction materials as required for achieving high power-conversion efficiency have, however, met with limited success. By incorporating a few volume per cent of alkanedithiols in the solution used to spin-cast films comprising a low-bandgap polymer and a fullerene derivative, the power-conversion efficiency of photovoltaic cells (air-mass 1.5 global conditions) is increased from 2.8% to 5.5% through altering the bulk heterojunction morphology. This discovery can potentially enable morphological control in bulk heterojunction materials where thermal annealing is either undesirable or ineffective.
高电荷分离效率，再加上与溶液处理相关的制造成本降低以及在柔性基板上实现的可能性，使得“塑料”太阳能电池成为未来光伏领域极具吸引力的选择。然而，按照实现高功率转换效率的要求，在本体异质结材料中控制供体/受体形态的尝试取得的成功有限。通过在用于旋涂包含低带隙聚合物和富勒烯衍生物的薄膜的溶液中加入百分之几体积的链烷二硫醇，通过改变本体异质结形态，光伏电池（空气质量1.5全球条件）的功率转换效率从2.8%提高到了5.5%。这一发现有可能在热退火不理想或无效的本体异质结材料中实现形态控制。
