Zhang Qiang, Atay Tolga, Tischler Jonathan R, Bradley M Scott, Bulović Vladimir, Nurmikko A V
Nat Nanotechnol. 2007 Sep;2(9):555-9. doi: 10.1038/nnano.2007.253. Epub 2007 Aug 19.
The integration of organic and inorganic semiconductors on the nanoscale offers the possibility of developing new photonic devices that combine the best features of these two distinct classes of material. Such devices could, for example, benefit from the large oscillator strengths found in organic materials and the nonlinear optical properties of inorganic species. Here we describe a novel hybrid organic/inorganic nanocomposite in which alternating monolayers of J-aggregates of cyanine dye and crystalline semiconductor quantum dots are grown by a layer-by-layer self-assembly technique. We demonstrate near-field photon-mediated coupling of vastly dissimilar optical excitations in the two materials that can reach efficiencies of up to 98% at room temperature. By varying the size of the quantum dots and thus tuning their optical resonance for absorption and emission, we also show how the ability of J-aggregates to harvest light can be harnessed to increase the effective absorption cross section of the quantum dots by up to a factor of ten. Combining organic and inorganic semiconductors in this way could lead to novel nanoscale designs for light-emitting, photovoltaic and sensor applications.
在纳米尺度上整合有机和无机半导体，为开发结合这两类不同材料最佳特性的新型光子器件提供了可能性。例如，这类器件可以受益于有机材料中发现的大振子强度以及无机材料的非线性光学特性。在此，我们描述了一种新型的有机/无机杂化纳米复合材料，其中通过逐层自组装技术生长出了由花菁染料的J -聚集体和晶体半导体量子点交替组成的单分子层。我们展示了两种材料中截然不同的光学激发之间的近场光子介导耦合，在室温下其效率可达98%。通过改变量子点的尺寸从而调整其吸收和发射的光学共振，我们还展示了如何利用J -聚集体捕获光的能力，将量子点的有效吸收截面提高多达十倍。以这种方式结合有机和无机半导体，可能会为发光、光伏和传感器应用带来新颖的纳米尺度设计。
