推广策略-A New Route to Study the Elastic Strain of ZnO Epilayer Grown on Sapphire.doc

A New Route to Study the Elastic Strain of ZnO Epilayer Grown on Sapphire
Zhenxing Feng
Grade 2000, Department of Technical Physics, School of Physics
Abstract
Good crystalline quality ZnO layer, %, was grown on sapphire (Al2O3) substrate by anic chemical vapor deposition (MOCVD). By using Rutherford backscattering (RBS)/channeling, the tetragonal distortion (eT) was determined. With the help of high resolution x-ray diffraction (XRD), not only the results of RBS/channeling were affirmed, but also the average perpendicular and parallel elastic strains can be calculated to be % and –% respectively.

ZnO is one of the wurtzite group Ⅱ-Ⅵ semiconductors, which have the similar properties to GaN [1]. ZnO, in the new century, gradually es the new focus in material research because it has a large direct band gap (Eg=, while Eg= for GaN [1]) at room temperature (RT), a high exciton binding energy (Eb=60meV, while Eb=28meV for GaN [2]) and a direct transition character. In addition, Zinc oxide has melting temperature as high as 2248K. The strength of Zn-to-O bond is larger than that of Ga-to-N. It is these excellent properties that make ZnO a good candidate material for optical devices, such as blue LED’s, and semiconductor devices besides widely used GaN[3].
In this paper, the ZnO epilayer was grown on sapphire (Al2O3) substrate by anic chem