Synthesis and Photoluminescence of Red to Near-Infrared-Emitting CdTe( x) Se(1−x) /CdZnS Core/Shell Quantum Dots.

Red to near-infrared (NIR)-emitting ternary-alloyed CdTe (x) Se(1−x) (x = 0–0.3) quantum dots (QDs) with tetrapod and dot morphologies have been synthesized by a facile method using oleic acid (OA) as single capping agent. The controlled dot-shaped and tetrapod-shaped CdTe( x) Se(1−x) QDs can be successfully obtained by adjusting the content of Te element. It is clear that CdTe (x) Se(1−x) QDs display the tunable emission peaks from the visible light (613.4 nm) to the NIR range (791.6 nm). With an inorganic CdZnS shell coated on the surface of CdTe(0.1)Se(0.9) cores, the stability and PL efficiency of the resulting core/shell QDs can be improved dramatically, accompanied with the red-shift of emission peaks to longer wavelength (795.6 nm). Peculiarly, a large blue shift of emission spectrum of CdTe(0.3)Se(0.7)/CdZnS core/shell QDs is observed, which is mainly ascribed to the shrink of the size of QDs by the fracture of tetrapod arms.