Cd与Se比例对CdSe量子点发光性能的影响

Effect of the elememtal ratio of Cd to Se on the luminescent properties of CdSe quantum dots

硒化镉(CdSe)量子点具有荧光量子产率高、稳定性好以及光谱易于调节等优点,在发光二极管、太阳能电池及荧光标记等领域有着广阔的应用前景,而研究不同工艺条件对其性能的影响具有重要意义.以金属氯化物为Cd和Se源,以巯基丙酸(3-MPA)为包覆剂利用水相回流反应法在100℃下反应120 min制备了系列CdSe量子点,并讨论了不同Cd与Se比例时样品的形貌、带隙及光学性能的变化.CdSe量子点的尺度在2.19~2.57 nm,最强激发峰位于431 nm,发射峰位于561 nm,吸收光谱带边从460 nm蓝移到450 nm,表明样品在合成过程中,Cd与Se比例对样品的性能有一定的影响.

Cadmium selenide(CdSe)quantum dots have the advantages of high fluorescence quantum yield,good stability and easy spectrum adjustment.They have broad application prospects in the fields of light-emitting diodes,solar cells and fluorescent labeling etc.It is of great significance to study the effects of different process conditions on their properties.Using mercaptopropionic acid(3-MPA)as coating agent,a series of CdSe quantum dots have been prepared by aqueous reflux reaction at 100℃for 120 min.The changes of morphology,band gap and optical properties of the samples with different elemental ratio of Cd to Se are discussed.The size of CdSe quantum dots is about 2.19 nm to 2.57 nm.The strongest excitation peak locates at 431 nm,the emission peak is at 561 nm,and the absorption spectrum blueshifts from 460 nm to 450 nm,indicating that the elemental ratio of Cd to Se has great influence on the properties of CdSe quantum dots.