Department of Chemical Engineering, University of Illinois at Chicago , 810 S. Clinton Street, Chicago, Illinois 60607, United States.
Department of Chemical Engineering, Indian Institute of Technology , Gandhinagar, Palaj, Gujarat 382355, India.
Nano Lett. 2017 Jul 12;17(7):4381-4389. doi: 10.1021/acs.nanolett.7b01458. Epub 2017 Jun 14.
Binding graphene with auxiliary nanoparticles for plasmonics, photovoltaics, and/or optoelectronics, while retaining the trigonal-planar bonding of sp hybridized carbons to maintain its carrier-mobility, has remained a challenge. The conventional nanoparticle-incorporation route for graphene is to create nucleation/attachment sites via "carbon-centered" covalent functionalization, which changes the local hybridization of carbon atoms from trigonal-planar sp to tetrahedral sp. This disrupts the lattice planarity of graphene, thus dramatically deteriorating its mobility and innate superior properties. Here, we show large-area, vapor-phase, "ring-centered" hexahapto (η) functionalization of graphene to create nucleation-sites for silver nanoparticles (AgNPs) without disrupting its sp character. This is achieved by the grafting of chromium tricarbonyl [Cr(CO)] with all six carbon atoms (sigma-bonding) in the benzenoid ring on graphene to form an (η-graphene)Cr(CO) complex. This nondestructive functionalization preserves the lattice continuum with a retention in charge carrier mobility (9% increase at 10 K); with AgNPs attached on graphene/n-Si solar cells, we report an ∼11-fold plasmonic-enhancement in the power conversion efficiency (1.24%).
将辅助纳米粒子与石墨烯结合用于等离子体、光伏和/或光电，同时保持 sp 杂化碳的三角平面键合以维持其载流子迁移率，这一直是一个挑战。石墨烯的传统纳米粒子掺入途径是通过“碳中心”共价功能化来创建成核/附着点，这会将碳原子的局部杂化从三角平面 sp 转变为四面体 sp。这破坏了石墨烯的晶格平面性，从而极大地降低了其迁移率和固有的优异性能。在这里，我们展示了大面积的气相“环中心”六配位（η）石墨烯功能化，以在不破坏其 sp 特性的情况下为银纳米粒子（AgNPs）创建成核位点。这是通过将三羰基铬[Cr(CO)]与石墨烯上苯环中的所有六个碳原子（σ键合）接枝来实现的，形成（η-石墨烯）Cr(CO) 络合物。这种非破坏性的功能化保留了晶格连续性，并保持了载流子迁移率（在 10 K 时增加 9%）；在石墨烯/n-Si 太阳能电池上附着 AgNPs 后，我们报告了功率转换效率（1.24%）提高了约 11 倍的等离子体增强。
