pH-Directed Aggregation to Control Photoconductivity in Self-Assembled Perylene Bisimides
pH-Directed Aggregation to Control Photoconductivity in Self-Assembled Perylene Bisimides
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DOI：
10.1016/j.chempr.2017.03.022
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发表时间：
2017-05-11
期刊：
影响因子：
23.5
通讯作者：
Adams, Dave J.
中科院分区：
文献类型：
--
作者：
Draper, Emily R.;Greeves, Benjamin J.;Adams, Dave J.
苝二酰亚胺（pbi）是一种有用的p共轭分子，可用于光电器件中作为具有强可见光吸收的n型材料。PBI可以自组装成一系列结构，但很少能够控制填料，使同一PBI可以形成h型或j型聚集体。这一点很重要，因为导电途径和光电子性能直接受到这种封装的影响。在这里，我们表明我们可以通过pH的细微变化来控制单个氨基酸功能化的PBI的包装。在一组条件下，当pH降低时，h型聚集体形成凝胶。在一组稍微不同的起始条件下，j型聚集体形成，但当pH降低时，它们不能形成凝胶。我们发现由自组装结构形成的薄膜具有非常不同的光导特性。
Perylene bisimides (PBIs) are one example of useful p-conjugated molecules that can be used in optoelectronic devices as n-type materials with strong visible light absorption. PBIs can self-assemble into a range of structures, but it is rare to be able to control the packing such that the same PBI can form either H-type or J-type aggregates. This is important because the conductivity pathways and optoelectronic properties are directly affected by this packing. Here, we show that we can control the packing of a single PBI functionalized with an amino acid by a subtle change in pH. Under one set of conditions, H-type aggregates form a gel when the pH is decreased. At a slightly different set of starting conditions, J-type aggregates are formed, but they cannot form a gel when the pH is lowered. We show that films formed from the self-assembled structures have very different photoconductive properties.