形貌可控纳米ZnO的制备及其光学性能研究

Research on Growth and Optical Performance of Morphology Controllable Nano-ZnO

以乙酸锌、氢氧化钠和柠檬酸钠为原料,利用水热法成功地实现了形貌可控纳米氧化锌(ZnO)粉体的制备,系统地研究了柠檬酸钠浓度、生长温度和后处理温度对纳米ZnO的形貌、光致发光和透过率等性能的影响。结果表明:随着柠檬酸钠的增加,纳米ZnO的形貌由短棒状到颗粒状再转变为花瓣状;降低生长温度,纳米ZnO的形貌从颗粒状转变为六方柱状;提高后处理温度,纳米ZnO的团聚方式由包覆式变为环绕式。室温光致发光(PL)谱显示,样品在387 nm左右处具有较强紫光发光峰、538 nm左右处具有较弱的绿光发光带。紫外-可见(UV-Vis)谱表明,在紫外光区,透过率均随波长的减小而降低;在可见光区,纳米ZnO的透过率随形貌由六方柱状构成的包覆式结构经短棒状转变到颗粒状、花瓣状、六方柱状构成的环绕式结构的转化而呈现降低的趋势。

Using Zn( CH_3COO)_2·6H_2O,Na(OH) and C_6H_5Na_3O_7·2H_2O as raw material,nano-ZnO powder with controllable morphology were prepared by hydrothermal method. The influences of concentration of Na_3C_6H_5O_7· 2H_2O,growth and heat treatment temperature on the morphology,photoluminescence and transmittance were investigated. The results show that the morphologies of nano-ZnO changed from short rod to granularity,and then to flower with the increase of concentration of Na_3C_6H_5O_7·2H_2O,and from granularity into hexagonal prism with reducing growth temperature. The aggregation pattern of nano-ZnO changed from sheathed type to around type with increasing heat treatment temperature. Room temperature photoluminescence spectra show that the samples have strong purple light emission peak at wavelength of 387 nm,and weak green light band at wavelength of 538 nm. UV-vis spectra show that the transmittance of nano-ZnO decreases as the wavelength in the ultraviolet range decreasing. The transmittance of nano-ZnO decreased with morphology transformation from sheathed type consists of hexagonal prism to short rod and to granularity and then finally to flower and finally to sheathed type consists of hexagonal prism in the visible light range.