Bandgap Engineering of Monodispersed Cu2-xSySe1-y Nanocrystals through Chalcogen Ratio and Crystal Structure

Bandgap engineering is important in light-absorption optimization of nanocrystals (NCs) for applications such as highly efficient solar cells. Herein, a facile one-pot method is developed to synthesize monodispersed ternary alloyed copper sulfide selenide (Cu2-xSySe1-y) NCs with tunable composition, structure, and morphology. The energy bandgaps can be tuned with the chalcogen ratio, and the crystal structure of the NCs is found to produce an effect on their bandgap and light absorption. The results are significant in bandgap engineering of semiconductor NCs.