Colloidal Cu-Zn-In-S-Based Disk-Shaped Nanocookies
Colloidal Cu-Zn-In-S-Based Disk-Shaped Nanocookies
复制标题
DOI：
10.1021/acs.chemmater.9b00005
复制
发表时间：
2019-04-23
影响因子：
8.6
通讯作者：
Lesnyak, Vladimir
中科院分区：
文献类型：
--
作者：
Lox, Josephine F. L.;Dang, Zhiya;Lesnyak, Vladimir
采用部分阳离子交换法制备了四元系铜锌铟S(CZIS)纳米小片。从合成侧向尺寸与nm相近、厚度与5 nm相近的高度单分散二元CuS NPLs入手，进一步进行了以In取代部分铜的阳离子交换反应，得到了CuIn-In-S NPLs。为了提高NPLs的稳定性和改善其光学性能，我们通过在NPLs上非均相成核和在粒子表面进行部分阳离子交换来实现ZnS壳层的生长。然而，后一种反应产生的是合金化而不是核/壳结构，而锌和硫前驱体之间的反应得到了不寻常的饼干状六方结构，其中硫化锌三角延伸只在板材厚度方向的一个基面上生长。随着硫化锌的生长，核/壳结构的CZIS/ZnS和合金化的CZIS NPLs的横向尺寸明显增大，分别接近80 nm和75 nm。光学性能分析表明，随着反应时间和温度的不同，CZIS非晶态发光材料的光致发光范围为780~820 nm。这种荧光信号主要来自合成过程中形成的副产物小纳米颗粒。与合金化的NPL相比，核/壳CZIS/ZnS微片的光致发光在近红外区有微弱的发射(光致发光最大值在近红外区)。1110 nm)，这在硫系铜基二维结构中还很少有报道。
We present a colloidal synthesis of quaternary Cu-Zn-In-S (CZIS) nanoplatelets (NPLs) by means of partial cation exchange. Starting with the synthesis of highly monodisperse binary CuS NPLs with lateral dimensions of similar to 64 nm and thickness of similar to 5 nm, we further performed a cation exchange reaction in which copper was partly replaced by indium, leading to Cu-In-S NPLs. To enhance the stability of the resulting NPLs and to improve their optical properties, we carried out the ZnS shell growth via both the heterogeneous nucleation of ZnS on the NPLs and via partial cation exchange on the surface of the particles. The latter reaction resulted, however, in rather an alloyed than the core/shell structure, whereas the reaction between zinc and sulfur precursors yielded unusual cookie-like hexagonal shaped structure, in which ZnS trigonal extensions grew only on one of the basal planes of the plates along the thickness direction. Upon ZnS growth, the lateral dimensions of the resulting core/shell CZIS/ZnS and alloyed CZIS NPLs distinctly increased to similar to 80 and similar to 75 nm, respectively. The analysis of the optical properties of the alloyed CZIS NPLs showed photoluminescence (PL) in the range from 780 to 820 nm depending on the reaction time and temperature. This PL signal originated mainly from small nanoparticles formed as a byproduct in the synthesis. In contrast to the alloyed NPLs, PL measurements of the core/shell CZIS/ZnS platelets showed a weak emission in the near-infrared region (PL maximum at approx. 1110 nm), which so far has rarely been reported for the copper chalcogenide-based two-dimensional structures.