Photosciences and Photonics Group, Chemical Sciences and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum-695019 (India).
Angew Chem Int Ed Engl. 2015 Jan 12;54(3):946-50. doi: 10.1002/anie.201408831. Epub 2014 Nov 27.
The formation of coaxial p-n heterojunctions by mesoscale alignment of self-sorted donor and acceptor molecules, important to achieve high photocurrent generation in organic semiconductor-based assemblies, remains a challenging topic. Herein, we show that mixing a p-type π gelator (TTV) with an n-type semiconductor (PBI) results in the formation of self-sorted fibers which are coaxially aligned to form interfacial p-n heterojunctions. UV/Vis absorption spectroscopy, powder X-ray diffraction studies, atomic force microscopy, and Kelvin-probe force microscopy revealed an initial self-sorting at the molecular level and a subsequent mesoscale self-assembly of the resulted supramolecular fibers leading to coaxially aligned p-n heterojunctions. A flash photolysis time-resolved microwave conductivity (FP-TRMC) study revealed a 12-fold enhancement in the anisotropic photoconductivity of TTV/PBI coaxial fibers when compared to the individual assemblies of the donor/acceptor molecules.
通过自组装的供体和受体分子的介观排列形成同轴 p-n 异质结对于实现基于有机半导体的组件中的高光电流产生非常重要，但这仍然是一个具有挑战性的课题。在此，我们表明，将 p 型π凝胶剂（TTV）与 n 型半导体（PBI）混合会形成自组装纤维，这些纤维同轴排列以形成界面 p-n 异质结。紫外/可见吸收光谱、粉末 X 射线衍射研究、原子力显微镜和 Kelvin 探针力显微镜揭示了分子水平上的初始自分类，以及随后的超分子纤维的介观自组装，导致同轴对齐的 p-n 异质结。闪光光解时间分辨微波电导率（FP-TRMC）研究表明，与供体/受体分子的各个组件相比，TTV/PBI 同轴纤维的各向异性光导率提高了 12 倍。
