CdTe1‐xSex/Cd0.5Zn0.5S core/shell quantum dots: core composition and property

Alloy CdTe1-xSex quantum dots (QDs) have been fabricated by an organic route using Cd, Te and Se precursors in a mixture of trioctylamine and octadecylphosphonic acid at 280 °C. The variation of photoluminescence (PL) peak wavelength of the CdTe1-xSex QDs compared with CdTe QDs confirmed the formation of an alloy structure. The Se component drastically affected the stability of CdTe1-xSex QDs. A Cd0.5Zn0.5S shell coating on CdTe1-xSex cores was carried out using oleic acid as a capping agent. CdTe1-xSex/Cd0.5Zn0.5S core/shell QDs revealed dark red PL while a yellow PL peak was observed for the CdTe1-xSex cores. The PL efficiency of the core/shell QDs was drastically increased (less than 1% for the cores and up to 65% for the core/shell QDs). The stability of QDs in various buffer solutions was investigated. Core/shell QDs can be used for biological applications because of their high stability, tunable PL and high PL efficiency. Copyright © 2013 John Wiley & Sons, Ltd.