飞秒激光辐照ZnO晶体

利用飞秒激光对ZnO晶体进行辐照，对辐照前后的晶体样品进行发光光谱及拉曼光谱检测。辐照后发光光谱的某些发光峰强度有明显增强，但未产生新的发光峰，表明没有新的缺陷结构产生，但晶体内锌空位、间隙位锌、间隙位缺陷浓度增加。拉曼光谱结果表明，辐照后ZnO晶体未产生相变，但随着辐照激光功率的增大，拉曼峰327 cm-1，437 cm-1强度明显减弱，表明在飞秒激光辐照作用下氧化锌的结晶程度下降。但574 cm-1峰值却随着辐照功率的增大而变大，分析表明该拉曼峰很可能是由于晶体内间隙位缺陷所致。同时实验过程中观察到飞

Femtosecond laser is used to irradiate ZnO crystal grown by hydrothermal method. Luminescence spectra and Raman spectra are measured before and after the laser irradiation. Luminescence spectra show the intensity of some emission peaks is increased after the irradiation, but no new emission peaks are found, indicating that no new crystal defects are formed and the concentrations of zinc vacancy, zinc interstitial and oxygen interstitials are increased. Raman spectra show no phase change occurs in ZnO crystal. The decrease of peak values for 327 cm-1 and 437 cm-1 show the crystallinity becomes worse. However, the 574 cm-1 peak value is increased with the increase of irradiation laser power, and this peak is related to zinc interstitial in all probability. Second-harmonic emission is observed during the experiment.