利用分子束磊晶製成硒化鎂鋅化合物及其特性研究

Abstract

本論文係利用光激螢光譜，X-Ray繞射儀及原子力顯微鏡，來研究由分子束磊晶法製作的硒化鎂鋅三元化合物之光學及結構特性。由光激螢光譜我們可以得知硒化鎂鋅之能隙及峰值半高寬隨著鎂濃度的增加而增大,但是與晶格缺陷有關的施子-受子對放射強度卻隨鎂濃度的增加而變小。由X-Ray繞射可得知晶格結構隨著鎂濃度的增加由zincblende結構轉變為rocksalt結構。由原子力顯微鏡可得知結晶粒隨鎂濃度的增加而變大。

In this work, we have investigated the photoluminescence (PL), x-ray diffraction (XRD), and atomic force microscope (AFM) properties of Zn1-xMgxSe alloys grown on (1 0 0 )GaAs substrates by molecular beam epitaxy (MBE). According to the data measured by PL showed that the bandgap and the full width at half maxima of the band-edge excitonic emission increase but the intensity of the defect-related donor-acceptor pairs emission decrease with increasing Mg composition in Zn1-xMgxSe alloys. The crystal structure is determined from XRD spectra and is found change from zincblende to rocksalt. By using the AFM, we have found the grain size increased as the Mg concentration was increased.