ZnO quantum-dots (QDs) capped with Cd were synthesized in dilute water-free solution with PVP K30 as a stabilizer and thiourea as a surface modification agent.The samples were characterized by UV absorption spectra, fluorescence emission spectra, Infrared spectra (IR), Transmission electron microscopy (TEM) and X-ray diffraction (XRD).The effects of optimization of matrix and the thiourea concentration on the optical properties of ZnO QDs were studied.The effects of Eu, Li doping on the optical properties of ZnO: Cd was also studied.The results showed that the fluorescence intensity of quantum dots increased obviously after the matrix optimized by doping Cd and doping Eu, Li.It maked particle size distribution more uniform, the grain size more smaller, the main peak blueshift and the yield of quantum dots increase with the use of the thiourea.The XRD peaks of the sample were the broad scattering peaks, and belonged to amorphous form.NH2 and C-NH2 stretching vibration absorption peaks were 3189.0 and 1088.2 cm-1 in infrared spectra as a result of thiourea.The best concentration of thiourea was 32 mg/mL.This method was simple, quantum dots prepared by this method obtained good stability and strong fluorescence intensity.The approach introduced in this paper laid a solid foundation for the biological markers and applications of the quantum-dots.%在非水稀溶液中以聚乙烯吡咯烷酮K-30为稳定剂,硫脲为表面修饰剂,制备Cd掺杂ZnO水溶性量子点荧光体;同时研究了基质的优化及硫脲含量对ZnO量子点发光性能的影响,Eu和Li的共掺杂对ZnO:Cd量子点发光性能的影响.采用紫外光谱、荧光发射光谱、红外光谱和透射电镜、XRD对样品进行表征.结果表明:经Cd优化基质后、Eu和Li的共掺杂使量子点荧光强度明显增强;硫脲修饰后纳米颗粒分布更加均匀、晶粒更小、荧光光谱蓝移、量子点产率增加;该样品XRD衍射峰是馒头峰.属于无定形态;红外光谱图中因硫脲引起的NH2和C-NH2伸缩振动吸收峰分别为3189.0,1088.2 cm-1,硫脲修饰的最佳浓度大约为32 mg/mL.该量子点制备方法简单易行,具有较好的稳定性及高荧光量子效率,为进一步应用于生物标记奠定基础.
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