Enhancement of the ultraviolet emission of ZnO nanorods by terphenyl liquid-crystalline ligands modification
Enhancement of the ultraviolet emission of ZnO nanorods by terphenyl liquid-crystalline ligands modification
复制标题
DOI：
10.1016/j.apsusc.2011.04.022
复制
发表时间：
2011-08
影响因子：
6.7
通讯作者：
Wei Chen;Fan Li;Yiwang Chen;K. Yuan;Lie Chen
中科院分区：
文献类型：
--
作者：
Wei Chen;Fan Li;Yiwang Chen;K. Yuan;Lie Chen
我们开发了一种以对己氧二苯基（HTph-OH）为液晶配体修饰ZnO纳米棒（ZnO NRs）表面的新方法。利用傅里叶变换红外光谱（FT-IR）、x射线衍射（XRD）和原子力显微镜（AFM）对改性ZnO nmr的结构和形貌进行了表征。原子力显微镜（AFM）测试表明，HTph-OH的表面改性和在其液晶温度（150℃）下的进一步退火处理可以显著改善ZnO nmr的分散性。退火后复合膜粗糙度的显著降低是由于退火后的HTph-OH链在介质诱导下自组织成更有序的结构，这可能推动ZnO NRs形成定向纳米分散结构。利用紫外-可见吸收光谱和光致发光光谱（PL）研究了改性ZnO nmr的光学性质。观察到明显增强的带边紫外光致发光和显著降低的缺陷相关发射。我们将这一观察结果归因于HTph-OH分子对ZnO NRs的近乎完美的表面钝化。同时，通过增加HTph-OH的浓度，并在其液晶温度下进行退火处理，可以进一步增强改性ZnO NRs的紫外发射。
We have developed a novel method to modifying the surface of ZnO nanorods (ZnO NRs) using p-hexoxyterphenylol (HTph-OH) as liquid crystal ligands. The structure and morphology of the modified ZnO NRs were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and atomic force microscopy (AFM). AFM measurement showed that the dispersion of ZnO NRs could be dramatically improved by the surface modification of HTph-OH and further annealing treatment at its liquid crystal state temperature (150 °C). The remarkable decrease of the annealed composite film roughness is because the HTph-OH chains self-organize into more ordered structure induced by mesogens after annealing treatment, which may push the ZnO NRs to form oriented nano-dispersing structure. The optical properties of the modified ZnO NRs were investigated by UV–vis absorption spectroscopy and photoluminescence spectroscopy (PL). Markedly enhanced band-edge ultraviolet photoluminescence and significantly reduced defect-related emission were observed. We attribute this observation to the nearly perfect surface passivation of the ZnO NRs by the HTph-OH molecules. Meanwhile, UV emission of modified ZnO NRs could be further enhanced by increasing the concentration of HTph-OH and annealing treatment at its liquid crystal state temperature.