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用透射电子显微镜 (TEM) ,X射线衍射(XRD)和光荧光谱 (PL)等测量手段研究了GaN薄膜的微结构和光学性质。样品是用光辐射加热MOCVD在蓝宝石衬底上制备的。随着衬底氮化时间的增加 ,扩展缺陷的密度显著增加。在位错密度增加一个数量级时 ,XRD摇摆曲线半宽度 (FWHM)由 1 1″增加到 1 5″,PL谱的黄光发射从几乎可忽略增加到带边发射强度的 1 0 0倍。结合生长条件 ,我们对黄光与微结构的关系作了讨论
The microstructure and optical properties of GaN films were investigated by means of transmission electron microscopy (TEM), X-ray diffraction (XRD) and fluorescence spectroscopy (PL). The samples were prepared on a sapphire substrate by photolithographic heating MOCVD. As the substrate nitridation time increases, the density of extended defects increases significantly. When the dislocation density increased by an order of magnitude, the FWHM of the XRD rocking curve increased from 11 “to 15”, and the yellow emission from the PL spectrum increased from almost negligible to 100 times the band edge emission intensity. In combination with the growth conditions, we discuss the relationship between yellow light and microstructure