Kamura Yoshio, Imura Kohei
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, Japan.
ACS Omega. 2019 Feb 14;4(2):3380-3384. doi: 10.1021/acsomega.9b00085. eCollection 2019 Feb 28.
Nanocarbon-based materials have excellent properties, including high electrical conductivity as well as charity-dependent optical absorption and luminescence; therefore, the materials are promising in applications for nanoelectric devices, nanophotonics, and so on. Carbon dots (CDs) are one of the carbon materials recently fabricated. Optical properties of CDs have been reported to be similar to those of polycyclic aromatic hydrocarbons (PAHs). For this reason, the CDs are considered to be composed of PAH. Synthesis of CDs has previously been accomplished through hydrothermal synthesis and microwave irradiation. These methods require a long synthesis time, and the processes involve multiple steps. In this study, we developed a fabrication method of CDs in simple and spatially selective ways, by using radical reactions in an organic polymer film with focused electron-beam irradiation. We investigated various organic polymers as reaction materials and found that polystyrene has a higher efficiency for CD formation than other organic polymers investigated. Absorption, photoluminescence, and Raman scattering properties of the electron-beam-irradiated sample were in good agreement with those reported for the CDs. The technique developed in this study is promising for fabricating light-emitting CDs and photonic crystals in a simple and flexible manner.
基于纳米碳的材料具有优异的性能，包括高导电性以及与电荷相关的光吸收和发光特性；因此，这些材料在纳米电子器件、纳米光子学等应用领域具有广阔前景。碳点（CDs）是近年来制备的碳材料之一。据报道，碳点的光学性质与多环芳烃（PAHs）相似。因此，碳点被认为是由多环芳烃组成的。此前，碳点的合成是通过水热合成和微波辐射来完成的。这些方法需要较长的合成时间，且过程涉及多个步骤。在本研究中，我们通过聚焦电子束辐照在有机聚合物薄膜中利用自由基反应，开发了一种简单且具有空间选择性的碳点制备方法。我们研究了各种有机聚合物作为反应材料，发现聚苯乙烯在形成碳点方面比其他所研究的有机聚合物具有更高的效率。电子束辐照样品的吸收、光致发光和拉曼散射特性与报道的碳点特性高度一致。本研究中开发的技术有望以简单且灵活的方式制备发光碳点和光子晶体。
