Cheng Hsin-Ming, Lin Kuo-Feng, Hsu Hsu-Cheng, Lin Chih-Jen, Lin Li-Jiaun, Hsieh Wen-Feng
Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Tahsueh Road., Hsinchu 30050, Taiwan, Republic of China.
J Phys Chem B. 2005 Oct 6;109(39):18385-90. doi: 10.1021/jp0533731.
Self-assembled secondary ZnO nanoparticles, recognized with the agglomeration of crystalline subcrystals, are successfully synthesized by a simple sol-gel method. TEM images display that one artificial cluster behaves in a single-crystal-like wurtzite structure because subcrystals coagulate as the same crystal orientation. Moreover, from the resonant Raman scattering, the as-grown sample exhibits phonon red shift; meanwhile, the coupling strength between electron and longitudinal optical phonon, determined by the ratio of second- to first-order Raman scattering cross sections, diminishes compared with the samples after postannealing at 350 and 500 degrees C. The size dependence of electron-phonon coupling is principally as a result of the Fröhlich interaction.
通过简单的溶胶-凝胶法成功合成了具有结晶亚晶团聚特征的自组装二级氧化锌纳米颗粒。透射电子显微镜图像显示，由于亚晶以相同的晶体取向凝聚，一个人工簇呈现出类似单晶的纤锌矿结构。此外，从共振拉曼散射来看，生长态样品表现出声子红移；同时，与在350℃和500℃进行后退火处理后的样品相比，由二阶与一阶拉曼散射截面之比确定的电子与纵向光学声子之间的耦合强度减小。电子-声子耦合的尺寸依赖性主要是弗罗利希相互作用的结果。
