Near-infrared and red dual-band luminescence from Cu2−xSeyS1−y–CdS core–shell heterostructured quantum dots

Abstract

The semiconductor–semiconductor nanoscale heterostructures have attracted great interest, especially for those where ion exchanges can take place at the interfaces to yield hybrid phases or doped nanocrystals. We study the photophysical properties of the synthesized type II energy band-aligned Cu2−xSeyS1−y–CdS core–shell heterostructured quantum dots. They exhibit rare simultaneous near-infrared (NIR) and red photoluminescence. The red luminescence originates from the excitons of the CdSeS phase at the core–shell interface region generated by a partial anion exchange at the interface. The broad NIR luminescence stems from the sulfur (selenium)-related defects in the heterostructures. These results reveal the fruitful photophysics in the ion-exchange-resultant semiconductor heteronanocrystals.