【摘要】 用溶胶-凝胶自燃烧法和高温固相法分别制备了纳米和体相SrAl2O4∶Eu,Dy长余辉磷光体。用X射线衍射对晶体结构进行了表征,用Keithley2410对材料在有无光照条件下的电流-电压特性进行了分析,同时还测量了样品的真空紫外激发光谱。光照使材料的电流增强,说明至少有部分电子经光照后被激发到导带;纳米材料真空紫外激发光谱发生蓝移,说明纳米材料的禁带宽度要大于体材料的禁带宽度,相同电压下纳米材料的电流小于体材料的电流。更多还原

【Abstract】 Nanoscale and bulk SrAl2O4∶Eu2+,Dy3+ were prepared respectively by auto-combustion of citrate gelatin and high temperature solid state method.The crystalline structure was examined by X-ray diffraction(XRD).The current-voltage characteristic was measured with a Keithley source meter 2 410.The VUV spectra were carried out with VUV spectrometer.The result showed that light irradiation increased the current,which indicates that some electrons are excited to the conduction band of host lattice.VUV excitation spectrum of nanoscale SrAl2O4∶Eu2+,Dy3+ shifts to the shorter wavelength relative to bulk material because it has narrower bandgap.As a result,the current of nanoscale material is weaker than that of the bulk one.更多还原