摘要
通过金属有机化学汽相沉积(MOCVD)法在GaAs衬底上生长出了MgxZn1-xO薄膜,通过氧气气氛下的高温退火使得衬底中的As原子通过扩散作用进入薄膜形成受主,得到p型的MgxZn1-xO薄膜。退火前后XPS谱中As(3d)峰的对比表明,MgxZn1-xO薄膜中存在As。电学测试结果表明:退火对样品的电阻率和载流子浓度的影响很大。这是长时间的氧气退火使得氧空位数目明显减少,从而使Zn—O键数量显著增加造成的。在样品的X射线衍射(XRD)谱中,p型样品的(002)衍射峰明显弱于n型样品。而在二者的光致发光(PL)谱中,都存在着很强的近带边发射(NBE)峰和较弱的深能级发射(DLE)峰,p型样品的NBE峰明显较弱而DLE峰却很强。这些现象是由于As原子的扩散,使薄膜中产生了新的缺陷能级,导致能级间的激子复合更加复杂。稳定的p型MgxZn1-xO薄膜的获得为制备MgxZn1-xO同质结和发光二极管奠定了基础。
p-type MgxZn1-xO film was grown on semi-insulating GaAs substrate by metal-organic chemical vapor deposition. The arsenic atoms, which acted as the acceptors in the film, were diffused from the substrates when the film was annealed in oxygen ambient at 700 ℃. And the cause of formation about p-type film was also discussed. The measurements, such as the XPS, HALL, XRD and PL were carried out. The existence of As in the film was proved by XPS. The resistivities and carrier concentrations of the film were measured by HALL effect measurement and the effect of anneal in the oxygen on them were discussed. The （002） peak in the XRD pattern and the NBE peak in the PL spectra of n-MgZnO were both stronger than that of p-MgZnO. The reason was believed that the new defects were introduced by As diffusion.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2008年第1期129-132,共4页
Chinese Journal of Luminescence
基金
国家自然科学基金资助项目(60576054,50532080)
