CdTe/CdSe核壳量子点的合成及其在指纹显现中的应用

以CdCl2和Te粉为原料,在水相中合成了CdTe量子点核;通过外延生长在CdTe量子点核上包覆一层CdSe量子点,得到具有良好荧光性能的CdTe/CdSe核壳量子点;采用X射线衍射仪、透射电镜、高分辨透射电镜分析了不同反应条件下合成的CdTe/CdSe核壳量子点的晶体结构和微观结构,并对其进行了荧光光谱等测试和指纹显现分析.结果表明,合成的CdTe和CdTe/CdSe量子点粒径在3～5nm之间,粒径分布窄,水分散性良好;可以通过控制反应时间和Te/Se比等得到在500～700nm显示荧光发射峰的CdTe/CdSe核壳量子点.此外,核壳CdTe/CdSe量子点可以有效地和指纹物质结合,可应用于对铝合金油潜指纹的鉴别.

Synthesis of CdTe/CdSe core-shell quantum dots and their application in developing fingerprint

Water-soluble fluorescent CdTe quantum dots （QDs） were synthesized in aqueous medium with CdC12 and Te powder as the starting materials. Then CdSe QDs were deposited onto CdTe QDs by epitaxial growth to form CdTe/CdSe core-shell quantum dots with good flu- orescence property. The crystal structure and microstructure of as-prepared CdTe/CdSe core- shell QDs synthesized at different reaction conditions were investigated by means of X-ray dif- fraction, transmission electron microscopy, and high-resolution transmission electron micros- copy. Moreover, fluorescence spectrometric analysis and fingerprint-developing test were also conducted for as-prepared CdTe/CdSe core-shell QDs. Results indicate that as-synthesized CdTe and CdTe/CdSe QDs, with uniform crystalline size of about 3-5 nm, can be well dis- persed in aqueous solution. By changing reflux time and ratio of Te to Se, it is feasible to pre- pare CdTe/CdSe QDs showing fluorescence emission at 500-700 nm. Besides, as-synthesized CdTe/CdSe QDs can be well combined with fingerprint-developing substances, showing promising application in identifying fingerprints like aluminum alloy latent fingerprints.