Synthesis, Structural, and Optical Properties of Stable ZnS:Cu,Cl Nanocrystals
Synthesis, Structural, and Optical Properties of Stable ZnS:Cu,Cl Nanocrystals
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DOI：
10.1021/jp809666t
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发表时间：
2009-04-23
影响因子：
2.9
通讯作者：
Zhang, Jin Z.
中科院分区：
文献类型：
--
作者：
Corrado, Carley;Jiang, Yu;Zhang, Jin Z.
以巯基丙酸（MPA）为封端分子，合成了稳定的水悬浮Cu+掺杂ZnS纳米晶。纳米晶体的特征在于使用的实验技术，包括紫外-可见光和光致发光（PL）光谱，X射线衍射（XRD），透射电子显微镜（TEM），电感耦合等离子体（ICP），和扩展的X射线吸收精细结构（EXAFS）的组合。紫外-可见电子吸收光谱在310 nm处显示出激子峰，这是量子限制ZnS纳米碳的特征。该激子峰不随Cu+掺杂而显著改变。XRD证实了ZnS纳米晶体的形成，并且通过TEM已经确定纳米C的平均尺寸为约6 nm。Cu+的掺入到ZnS中表现为在添加在合成反应期间被还原成Cu+的Cu 2+时PL光谱中的发射带的显著红移。获得EXAFS数据以确认Cu掺杂以及确定NC中Cu+和Zn 2+的局部结构。拟合的EXAFS数据Cu+表明，大多数Cu+离子位于表面附近的ZnS NC和一个显着的分数可能是在块状材料中发现的CuS的形式。这些结合的光学和结构的研究提供了重要的新的洞察相关的电子能级和它们的相关性的ZnS：Cu，Cl纳米粒子的光学和结构特性。这对这种磷光体材料用于固态照明、成像和其他光子器件的潜在应用具有重要意义。
Stable water-suspendable Cu+-doped ZnS nanocrystals (NCs) have been synthesized with mercaptopropionic acid (MPA) as a capping molecule. The nanocrystals have been characterized using a combination of experimental techniques including UV-vis and photolurminescence (PL) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma (ICP), and extended X-ray absorption fine structure (EXAFS). The UV-vis electronic absorption spectrum shows an excitonic peak at 310 nm, characteristic of quantum-confined ZnS NCs. This excitonic peak does not change noticeably with Cu+ doping. XRD confirms the formation of ZnS nanocrystals, and the average size of the NCs has been determined to be around 6 nm by TEM. The incorporation of Cu+ into the ZnS is manifested as a substantial red-shift of the emission band in the PL spectra upon addition of Cu2+ that was reduced into Cu+ during the synthesis reaction. EXAFS data were obtained to confirm copper doping as well as determine the local structure about Cu+ and Zn2+ in the NCs. Fitting to the EXAFS data for Cu+ suggests that most Cu+ ions are located near the surface within the ZnS NCs and that a significant fraction may be in the form of CuS as found in bulk material. These combined optical and structural studies have provided important new insight into the relevant electronic energy levels and their correlation to the optical and structural properties of ZnS:Cu,Cl NCs. This has important implications in potential applications of this phosphor material for solid state lighting, imaging, and other photonic devices.