高分子网络凝胶法制备ZnO超细粉体及其光学性能  

Synthesis of Spherical ZnO Ultrafine Powder by Polymer Network Gel Method and Photoluminescence Spectrum Characters

作　　者：李江勇[1] 李岚[1] 李海燕[2] 张晓松[1,3] 庄晋艳[1] 

机构地区：[1]天津理工大学材料物理研究所,天津市光电显示材料与器件重点实验室,显示材料与光电器件教育部重点实验室,天津300384 [2]天津大学电子信息工程学院,天津300172 [3]南开大学现代光学研究所,天津300171

出　　处：《发光学报》2008年第1期133-138,共6页Chinese Journal of Luminescence

基　　金：天津市科技创新能力与环境建设平台项目(06TXTJJC14600);天津市自然科学基金(07JCYBJC06400);天津市高等学校科技发展基金计划资助项目

摘　　要：采用高分子网络凝胶法制备球形ZnO超细粉体。通过聚乙烯醇（PVA）亚浓溶液交联网络的空间位阻作用，经过烧结，获得了具有球形形貌的粒径为1—3μm的ZnO粉体颗粒。利用X射线衍射（XRD）、扫描电镜（SEM）分析了不同PVA浓度以及退火温度对产物形貌、结构的影响，发现在PVA溶液浓度为5％，并且经500℃热处理所形成的ZnO球形颗粒最为均匀规整。研究了球形ZnO粉体的光致发光性能，室温下经325nm波长激发，观察到两个中心波长分别位于407，468nm的微弱的荧光发射带，在合适温度下，在385nm处还出现了较强的紫外峰。PL光谱表明，退火温度对ZnO的光致发光影响较大，随着退火温度升高，由于表面缺陷和结晶性能发生变化，407nm处发射峰逐渐减弱消失，而紫外发光先增强后减弱，经500℃热处理样品的紫外发光性能达到最佳。Micrometer-sized spherical ZnO uhrafine powder was prepared by polyvinyl alcohol gel method. Zinc acetate was used as starting material, polar polymer polyvinyl alcohol with long chain was used as grids localization and lattice reagent to control nucleation and crystal growth via ionic complexation between the hydroxy groups and Zn^2＋ ions. The products were obtained by changing thermal treatment under controlling rise rate. The as-prepared ZnO powder was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and photoluminescence （PL） spectra. The analytical results of SEM and XRD indicate that the concentrations of the PVA solution, sintering temperature are the factors influencing the preparation. It is found that the uniform spherical ZnO with diameter about 1 - 3 μm are obtained under the conditions of a PVA concentration of 5 % and sintering temperature of 500 ℃ at which most of polymer are removed after 3 h. The PL spectra of these samples include two blue emission peaks, centered at 407 nm which is attributed to the zinc vacancies and 468 nm which is due to the transition of electrons from the level of the ionized oxygen vacancies to the valence band at room temperature when excited with 325 nm light. The ultraviolet emission peak located at 385 nm which originates from the interband transition of electrons has been observed at certain temperature. It is found that the intensities of these peaks vary with annealing temperature. With increasing the heat treatment temperature, the blue emission peak at 407 nm gradually disappears. The intensities of ultraviolet emission peaks are sharply enhanced and approach a maximum value for the sample prepared at 500 ℃, then it decreases as the annealing temperature increase up to 600 ℃.

关 键 词：高分子网络凝胶法 聚乙烯醇 球形ZnO PL光谱 

分 类 号：O482.31[理学—固体物理]