Feng Jian, Yang Xiaosheng, Li Rong, Yang Xianjiong, Feng Guangwei
State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550014, Guizhou, China.
Department of Chemistry, School of Basic Medical Science, Guizhou Medical University, 9 Beijing Road, Guiyang 550004, Guizhou, China.
Micromachines (Basel). 2019 Jul 1;10(7):439. doi: 10.3390/mi10070439.
A facile hot injection approach to synthesize high-quality non-stoichiometric ZnAgInS nanocrystals (NCs) in the size range of 2.8-3.1 nm was presented. The fluorescence spectra had single band gap features, and indicated the formation of alloy states rather than simple composite structures. The chemical compositions, photoluminescence (PL) emission wavelengths, and quantum yields of ZnAgInS nanocrystals were significantly influenced by the concentration of an organic capping agent. The appropriate proportion of 1-dodecanthiol in the precursor prevented the precipitation, increased the fluorescence quantum yield, and improved their optical properties. The proper ratio of capping agent allowed Zn, Ag, and In to form a better crystallinity and compositional homogeneity of ZnAgInS nanocrystals. The photoluminescence was tunable from blue to red in the range of 450-700 nm as the Ag content changed independently. The PL and absorption spectra of ZnAgInS nanocrystals showed a significant blue shift with the decrease of Ag content in the precursor. As there were no obvious differences on the average particle sizes of ZnAgInS samples, these results fully revealed the composition-dependent photoluminescence properties of ZnAgInS nanocrystals. The relative quantum yield reached 35%. The fluorescence lifetimes (τ=115-148 ns and τ=455-483 ns) were analogous to those of AgInS and (AgIn)ZnS.
本文提出了一种简便的热注入方法，用于合成尺寸范围为2.8-3.1 nm的高质量非化学计量比ZnAgInS纳米晶体（NCs）。荧光光谱具有单带隙特征，表明形成了合金态而非简单的复合结构。ZnAgInS纳米晶体的化学成分、光致发光（PL）发射波长和量子产率受有机封端剂浓度的显著影响。前驱体中1-十二烷硫醇的适当比例可防止沉淀，提高荧光量子产率，并改善其光学性质。封端剂的适当比例使Zn、Ag和In形成更好的结晶度和ZnAgInS纳米晶体的成分均匀性。随着Ag含量独立变化，光致发光在450-700 nm范围内可从蓝色调至红色。随着前驱体中Ag含量的降低，ZnAgInS纳米晶体的PL和吸收光谱出现明显的蓝移。由于ZnAgInS样品的平均粒径没有明显差异，这些结果充分揭示了ZnAgInS纳米晶体的成分依赖光致发光性质。相对量子产率达到35%。荧光寿命（τ=115-148 ns和τ=455-483 ns）与AgInS和(AgIn)ZnS的荧光寿命相似。
