液体石蜡体系中CdSeS三元量子点的制备及性能

Preparation and Properties of High-quality CdSeS Alloyed Quantum Dots in Liquid Paraffin

采用液体石蜡为反应溶剂,油酸为Cd源的溶剂和配体,在无磷条件下通过用高温热解法合成了高质量的CdSeS三元合金量子点.用透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)和能量色散X射线分析仪(EDX)等对产物的性能进行了表征.结果表明,反应温度、反应时间和Se与S的比例等因素均对量子点的生长过程及光学性能产生影响.采用该方法制得的CdSeS三元合金量子点均为立方闪锌矿结构,且形成了一种内富S外富Se的成分梯度结构,其最大发射波长可在370～595 nm(近紫外～橙红色)范围内连续可调,量子效率最高可达65%.该体系下制备的CdSeS三元量子点具有良好的热稳定性和光稳定性.

A phosphine-free route was successfully developed to prepare highly-quality cadmium selenium sulfide（CdSeS） alloyed quantum dots（QDs） using paraffin liquid as the reaction solvent and oleic acid as the ligand.The effects of the reaction temperature,growth time,and the molar ratio of S to Se on the properties of the CdSeS QDs were investigated.The as-prepared alloyed CdSeS QDs with zinc-blend crystalline structure possess a broad emission spectral ranging from 370 nm to 595 nm（from near-ultraviolet to salmon pink） and high photoluminescence quantum yield（PLQY） up to 65%.Moreover,the as-prepared alloyed CdSeS QDs with a gradient ＂CdS-rich core/CdSe-rich surface＂ structure also demonstrate good optical stabilities against the temperature change and photobleaching,which suggests their promising application on photoelectric devices and biological fluorescent labeling.