Synthesis of Color-Tunable CdSe Nanocrystals via a Green Synthetic Method

In this letter, ascorbic acid was used as a novel and environmental friendly reducing agent in the synthesis of high-quality L-cysteine-capped CdSe nanocrystals. The X-ray diffraction and high-resolution transmission electron microscope results show that the as-prepared CdSe quantum dots (QDs) had a cubic crystal structure with an average size of 5 nm. The synthetic conditions were optimized by adjusting the n(L-Cys)/n(Cd
²⁺
), pH, and Cd/Se molar ratios. Under optimum conditions, the quantum yield of CdSe QDs reached 22%.