• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nanotechnology >Non-heavy-metal ZnS quantum dots with bright blue photoluminescence by a one-step aqueous synthesis
【24h】

Non-heavy-metal ZnS quantum dots with bright blue photoluminescence by a one-step aqueous synthesis

机译：一步水合法合成具有亮蓝色光致发光的非重金属ZnS量子点

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have examined the aqueous synthesis of non-heavy-metal ZnS, quantum dots (QDs) using 3-mercaptopropionic acid (MPA) as the capping molecule at various pH and MPA:Zn:S ratios. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) indicated that the aqueous ZnS QDs were 3-5 nm in size with a zinc blende structure. We showed that, at pH 12 with a MPA:Zn:S = 8:4:1 ratio, the ZnS QDs with optimal blue emission could be obtained in a one-step, room-temperature aqueous process that exhibited a quantum yield of 31 percent, higher than that of the commercial CdSe/ZnS core-shell QDs. The present ZnS QDs could pass through a 50 kD filter. This indicated that they were smaller than 5 nm in size, consistent with those estimated from the UV-vis absorption edge and the TEM image. At a lower pH (e.g. pH = 8), the room-temperature synthesized ZnS QDs exhibited no photoluminescence. Although further hydrothermal annealing at 100 deg C could improve the photoluminescence of the ZnS QDs, the resultant emission was not as bright as that obtained at pH 12 at room temperature. The blue emission of aqueous ZnS QDs was likely the result of trap-state emissions involving the defect states of the QDs. The present ZnS QDs were bright, small and contained non-heavy-metal elements, thus offering the Potential for in vivo bioimaging.
机译：我们已经研究了使用3-巯基丙酸（MPA）作为封端分子在各种pH和MPA：Zn：S比率下的非重金属ZnS量子点（QD）的水合成。透射电子显微镜（TEM）和X射线衍射（XRD）表明，水性ZnS QD尺寸为3-5 nm，具有锌共混物结构。我们表明，在pH为12且MPA：Zn：S = 8：4：1的情况下，可以通过一步式室温水处理获得具有最佳蓝光发射的ZnS QD，其量子产率为31百分比，高于商用CdSe / ZnS核壳量子点。当前的ZnS QD可以通过50 kD滤波器。这表明它们的尺寸小于5 nm，与从UV-vis吸收边缘和TEM图像估计的尺寸一致。在较低的pH（例如pH = 8）下，室温合成的ZnS QD不会显示光致发光。尽管在100摄氏度下进一步进行水热退火可以改善ZnS QD的光致发光，但所产生的发射并不像室温下在pH 12下获得的那样明亮。水性ZnS量子点的蓝色发射很可能是陷阱态发射的结果，涉及到量子点的缺陷状态。当前的ZnS QD明亮，小巧且包含非重金属元素，因此为体内生物成像提供了潜力。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号