Stergiou Anastasios, Sideri Ioanna K, Kafetzi Martha, Ioannou Anna, Arenal Raul, Mousdis Georgios, Pispas Stergios, Tagmatarchis Nikos
Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece.
Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, Mariano Esquillor s/n, 50018 Zaragoza, Spain.
Nanomaterials (Basel). 2022 Apr 8;12(8):1275. doi: 10.3390/nano12081275.
Development of graphene/perovskite heterostructures mediated by polymeric materials may constitute a robust strategy to resolve the environmental instability of metal halide perovskites and provide barrierless charge transport. Herein, a straightforward approach for the growth of perovskite nano-crystals and their electronic communication with graphene is presented. Methylammonium lead bromide (CHNHPbBr) nano-crystals were grown in a poly[styrene-co-(2-(dimethylamino)ethyl methacrylate)], P[St-co-DMAEMA], bi-functional random co-polymer matrix and non-covalently immobilized on graphene. P[St-co-DMAEMA] was selected as a bi-modal polymer capable to stabilize the perovskite nano-crystals via electrostatic interactions between the tri-alkylamine amine sites of the co-polymer and the A-site vacancies of the perovskite and simultaneously enable Van der Waals attractive interactions between the aromatic arene sites of the co-polymer and the surface of graphene. The newly synthesized CHNHPbBr/co-polymer and graphene/CHNHPbBr/co-polymer ensembles were formed by physical mixing of the components in organic media at room temperature. Complementary characterization by dynamic light scattering, microscopy, and energy-dispersive X-ray spectroscopy revealed the formation of uniform spherical perovskite nano-crystals immobilized on the graphene nano-sheets. Complementary photophysical characterization by UV-Vis absorption, steady-state, and time-resolved fluorescence spectroscopy unveiled the photophysical properties of the CHNHPbBr/co-polymer colloid perovskite solution and verified the electronic communication within the graphene/CHNHPbBr/co-polymer ensembles at the ground and excited states.
由聚合物材料介导的石墨烯/钙钛矿异质结构的开发可能构成一种强有力的策略，以解决金属卤化物钙钛矿的环境不稳定性并提供无障碍电荷传输。在此，提出了一种用于钙钛矿纳米晶体生长及其与石墨烯进行电子通信的直接方法。甲基溴化铅铵（CH₃NH₃PbBr₃）纳米晶体在聚[苯乙烯-co-（甲基丙烯酸2-（二甲基氨基）乙酯）]，P[St-co-DMAEMA]双功能无规共聚物基质中生长，并通过非共价方式固定在石墨烯上。选择P[St-co-DMAEMA]作为一种双峰聚合物，它能够通过共聚物的三烷基胺胺位点与钙钛矿的A位空位之间的静电相互作用来稳定钙钛矿纳米晶体，同时使共聚物的芳族芳烃位点与石墨烯表面之间产生范德华吸引力相互作用。新合成的CH₃NH₃PbBr₃/共聚物和石墨烯/CH₃NH₃PbBr₃/共聚物组合是通过在室温下将各组分在有机介质中物理混合而形成的。通过动态光散射、显微镜和能量色散X射线光谱进行的补充表征揭示了固定在石墨烯纳米片上的均匀球形钙钛矿纳米晶体的形成。通过紫外-可见吸收、稳态和时间分辨荧光光谱进行的补充光物理表征揭示了CH₃NH₃PbBr₃/共聚物胶体钙钛矿溶液的光物理性质，并验证了石墨烯/CH₃NH₃PbBr₃/共聚物组合在基态和激发态下的电子通信。
