退火对ZnO薄膜结构及发光特性的影响

Effects of Annealing on the Structure and Photoluminescence of ZnO Thin Films

生长在蓝宝石C面上的ZnO薄膜是通过等离子体金属有机物化学汽相淀积方法获得的 ,由其X光衍射得知 ,生长过程中分段退火和最后退火在薄膜中分别引入了张应力和压应力。通过对样品光致发光光谱研究表明 :分段退火样品在 380nm附近出现了单一激子发射峰 ,而最后退火样品却出现了与应变有关的Γ5和Γ6两激子发射峰 ,同时在两者的光致发光光谱中与深能级有关的荧光峰都未出现。

ZnO films have been grown on C-plane sapphire substrate with the plasma-assisted metal-organic chemical vapor deposition (MOCVD) method. By using the X-ray diffraction (XRD) and calculation, it is found that there is tensile strain in the sample annealed for many times during the growing process, and compressive strain in the sample which is annealed only one time after growth. The photoluminescence spectra show that there is only one emitting peak at around 380nm for the sample annealed for many times and two peaks for the sample annealed for one time after growing.