Abnormal strong burn-in degradation of highly efficient polymer solar cells caused by spinodal donor-acceptor demixing.
Abnormal strong burn-in degradation of highly efficient polymer solar cells caused by spinodal donor-acceptor demixing.
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DOI：
10.1038/ncomms14541
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发表时间：
2017-02-22
影响因子：
16.6
通讯作者：
Brabec CJ
中科院分区：
文献类型：
--
作者：
Li N;Perea JD;Kassar T;Richter M;Heumueller T;Matt GJ;Hou Y;Güldal NS;Chen H;Chen S;Langner S;Berlinghof M;Unruh T;Brabec CJ
有机太阳能电池的性能取决于精细的、精心优化的体异质结微观结构，它由精细混合和相对分离的供体/受体区域组成。在这里，我们证明了在高效聚合物太阳能电池中，由于供体相和受体相的分离，导致了异常强烈的灼烧降解，这大大减少了电荷的产生，这可以归因于两种材料固有的低混溶性。尽管微观结构可以通过动力学调整来实现高性能，但在固体状态下，即使在室温和黑暗中，供体和受体固有的低混溶性也会导致自发相分离。分子参数的理论计算和spinodal相图的构建强调了供体和受体之间的分子不相容是烧损降解的主要机制，这是迄今为止降低有机太阳能电池性能和稳定性的主要短时间损失。Li等人从形态学角度研究了有机光伏电池的降解。他们发现供体相和受体相通过spinodal分解进行过度脱混，导致电荷产生减少。脱混是由于两种材料固有的低混相性。
The performance of organic solar cells is determined by the delicate, meticulously optimized bulk-heterojunction microstructure, which consists of finely mixed and relatively separated donor/acceptor regions. Here we demonstrate an abnormal strong burn-in degradation in highly efficient polymer solar cells caused by spinodal demixing of the donor and acceptor phases, which dramatically reduces charge generation and can be attributed to the inherently low miscibility of both materials. Even though the microstructure can be kinetically tuned for achieving high-performance, the inherently low miscibility of donor and acceptor leads to spontaneous phase separation in the solid state, even at room temperature and in the dark. A theoretical calculation of the molecular parameters and construction of the spinodal phase diagrams highlight molecular incompatibilities between the donor and acceptor as a dominant mechanism for burn-in degradation, which is to date the major short-time loss reducing the performance and stability of organic solar cells. Li et al. study degradation in organic photovoltaics from a morphological perspective. They find that donor and acceptor phases undergo excessive demixing via spinodal decomposition resulting in a reduction of charge generation. Demixing is due to the inherently low miscibility of both materials.