Facile and Purification-Free Synthesis of Nitrogenated Amphiphilic Graphitic Carbon Dots

The emerging carbon-based quantum dots have been attracting attention because of their tremendous potential for optoelectronic and biomedical applications, which is due to their unique and size-tunable optical properties, their ability to be functionalized, and their biocompatibility. Here, we report the facile one-step synthesis of highly fluorescent and amphiphilic n-doped graphitic carbon dots (N-GCDs) using a fumaronitrile (FN) precursor. An interesting property of the prepared GCDs is their near pH neutral dispersibility without refinement, which stands in contrast to reported methods. This finding indicates that our approach could lead to low-cost and efficient processability that is scalable and environmentally friendly. In addition, we find that our N-GCDs have high density of graphitic structure such as sp²-hybridized carbon and tiny amounts of defect by near-edge X-ray absorption fine structure (NEXAFS) results. Finally, to confirm the electro-optical behavior of N-GCDs on photovoltaic devices, we fabricate iPSCs consisting of ITO/PEIE/PTB7:PC₇₁BM (+ N-GCDs)/MoO₃/Ag. Using this effective approach, we demonstrate the highest conversion efficiency of â∼ 8.6% resulting from improved photoresponsibility and charge transport based on various charge and energy transfer dynamics. Also, we believe that the shape, size and functionality of these GCDs can be controlled using other chemical species to provide a variety opportunities for use in optoelectronics, biological applications, and sensors.