Solution phase synthesis of homogeneously alloyed ultrathin CdS_xSe_1-x nanosheets

Provided that precise control could be achieved over their optoelectronic properties, semiconductor two-dimensional (2D) nanosheets with a thickness of a few monolayers would constitute appealing building blocks. It is well established that alloying promotes efficient bandgap engineering, but divergent precursor reactivities have so far prevented the production of homogeneously alloyed 2D structures. We report a simple synthesis of alloyed CdS_xSe_1-x that preserves the 2D nature. High resolution microscopy reveals their edge structure and atomic rearrangement within the layer. Their optical properties show a comparable or higher quantum yield relative to pure nanosheets, making them promising materials for various applications.