Control growth of PbS quantum dots doped sono-ormosil
Control growth of PbS quantum dots doped sono-ormosil
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DOI：
10.1557/jmr.2001.0353
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发表时间：
2001-09
影响因子：
2.7
通讯作者：
R. Erce-Montilla;M. Piñero;N. Rosa-Fox;A. Santos;L. Esquivias
中科院分区：
文献类型：
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作者：
R. Erce-Montilla;M. Piñero;N. Rosa-Fox;A. Santos;L. Esquivias
采用溶胶-凝胶法，利用高功率超声合成了半导体PbS量子点掺杂SiO_2有机改性硅酸盐（ormosil）凝胶。研究了PbS晶体浓度和3-巯丙基三甲氧基硅烷作为表面封端剂（SCA）的加入对PbS晶体生长的影响。通过调节SCA与铅的比例，得到不同尺寸和形貌的PbS纳米颗粒。由N_2物理吸附等温线计算了织构参数。PbS方铅矿相通过X射线衍射、晶体尺寸通过高分辨率透射电子显微镜和激子约束通过紫外-可见-近红外分光光度法鉴定。获得了不同PbS和SCA浓度的球和立方体的微晶平均尺寸为6.5至10.5 nm，针宽7 nm，长15-20 nm。这些结果不同于有效质量近似证实的最小的纳米晶体的带隙修改预测。该方法允许控制晶体尺寸并改善PbS纳米晶体的稳定性。
Semiconductor PbS quantum dots doped-SiO_2 organically modified silicate (ormosil) gels were synthesised via sol-gel by using high-power ultrasounds (sonogel). The effect of PbS crystal concentration and the addition of (3-mercaptopropyl)trimethoxysilane acting as surface capping agent (SCA) were investigated. By adjustment of the SCA to lead ratio, PbS nanoparticles of different sizes and morphologies were obtained. Textural parameters were calculated from N_2 physisorption isotherms. The PbS galena phase was identified by x-ray diffraction, the crystal size by high-resolution transmission electron microscopy, and the exciton confinement by ultraviolet–visible–near-infrared spectrophotometry. Crystallite mean sizes of spheres and cubes ranging from 6.5 to 10.5 nm and needles 7-nm wide and 15–20 nm long, for different PbS and SCA concentrations, were obtained. These results differ from those predicted by the effective mass approximation corroborating the band gap modifications in the smallest nanocrystals. The method allows the control of the crystal size and improves the stabilization of the PbS nanocrystals.