Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Nano Lett. 2011 Jul 13;11(7):2655-9. doi: 10.1021/nl200679n. Epub 2011 May 26.
J-aggregates are ordered clusters of coherently coupled molecular dyes, (1) and they have been used as light sensitizers in film photography due to their intense absorptions. Hybrid structures containing J-aggregates may also have applications in devices that require spectral specificity, such as color imaging or optical signaling. (2) However the use of J-aggregates in optoelectronic devices has posed a long-standing challenge (3, 4) due to the difficulty of controlling aggregate formation and the low charge carrier mobility of many J-aggregates in solid state. In this paper, we demonstrate a modular method to assemble three different cyanine J-aggregates onto CdSe nanowires, resulting in a photodetector that is color-sensitized in three specific, narrow absorption bands. Both the J-aggregate and nanowire device components are fabricated from solution and the sensitizing wavelength is switched from blue to red to green, using only solution-phase exchange of the J-aggregates on the same underlying device.
J- 聚集体是有序的分子染料聚集体，（1）由于其强烈的吸收，它们已被用作薄膜摄影中的光增感剂。含有 J- 聚集体的混合结构也可能在需要光谱特异性的设备中得到应用，例如颜色成像或光学信号。（2）然而，由于难以控制聚集体的形成以及许多 J- 聚集体在固态中的载流子迁移率低，因此 J- 聚集体在光电设备中的应用一直是一个长期存在的挑战（3,4）。在本文中，我们展示了一种将三种不同的菁 J- 聚集体组装到 CdSe 纳米线上的模块化方法，从而制造出一种在三个特定的窄吸收带中光增感的光电探测器。J- 聚集体和纳米线器件组件均由溶液制备，并且仅通过在相同的基础器件上进行 J- 聚集体的溶液相交换，就可以将增感波长从蓝色切换到红色再到绿色。
