铜掺杂氧化锌纳米棒的非线性光学响应竞争特性

发布时间：2018-11-08 08:17

【摘要】：利用飞秒脉冲激光激发Cu掺杂ZnO纳米棒,研究其特有的非线性光学性质和激发机制。在激发波长为750 nm的荧光光谱中,二次谐波峰非常弱,几乎可以忽略,存在非常强的激子发光峰和Cu掺杂导致缺陷发光峰。激发强度的增大会导致这两个发光峰强度呈非线性增大,激子发光峰位产生明显红移,而缺陷发光峰位没有变化。进一步增大激发强度,缺陷发光峰强度会出现饱和甚至有所下降,而激子发光峰强度持续增大。当激发波长增加到760 nm时,从样品的荧光光谱可以清楚地识别到二次谐波峰和激子发光峰以及缺陷发光峰并存。随着激发波长的进一步增加,二次谐波强度不断增大,而激子发光峰和缺陷发光峰的强度却随之下降。当激发波长为790 nm和800 nm时,未发现激子发光峰和缺陷发光峰,非线性光谱以二次谐波为主导。研究结果表明,通过选择合适的激发波长和激发强度,可以实现发光颜色的转变,使得Cu掺杂ZnO纳米棒在全光显示方面具有潜在的发展前景。
[Abstract]:The unique nonlinear optical properties and excitation mechanism of Cu doped ZnO nanorods were investigated by femtosecond pulsed laser excitation. In the fluorescence spectrum with excitation wavelength of 750 nm, the second harmonic peak is very weak and can be almost ignored. The existence of very strong exciton emission peak and Cu doping lead to defect luminescence peak. The increase of excitation intensity leads to the nonlinear increase of the intensity of the two peaks, and the red shift of the exciton emission peak, while the defect luminescence peak does not change. When the excitation intensity is further increased, the peak intensity of the defect emission peak will saturate or even decrease, while the intensity of the exciton peak will continue to increase. When the excitation wavelength is increased to 760 nm, the second harmonic peak, exciton emission peak and defect luminescence peak can be clearly identified from the fluorescence spectra of the sample. With the further increase of excitation wavelength, the second harmonic intensity increases, while the intensity of exciton emission peak and defect emission peak decrease. When the excitation wavelength is 790 nm and 800 nm, no exciton emission peak and defect luminescence peak are found, and the nonlinear spectrum is dominated by second harmonic. The results show that Cu doped ZnO nanorods have a potential development prospect in all optical display field by choosing appropriate excitation wavelength and excitation intensity.
【作者单位】：广东技术师范学院光电工程学院;闽南师范大学物理与信息工程学院;
【基金】：国家自然科学基金(61475038,11174061,61675001) 广东省教育厅项目(2014KZDXM059)资助~~
【分类号】：O472.3

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