摘要
对厚度不同的样品进行了XRD和PL谱测量,由(0002)面、(30-32)面的摇摆曲线的半峰宽值和GaN(0002)衍射峰位置计算了样品的刃位错、螺旋位错的密度以及C轴应变,实验结果表明厚度增加后GaN薄膜中的刃位错、螺旋位错密度及C轴薄膜应力均得到减小,而PL谱带边峰和蓝带强度显著增强。分析认为:厚度增加后,位错减少是由材料生长过程中位错的合并和湮灭作用造成的;样品PL谱的带边峰和蓝带强度显著增强是因为位错引入的非辐射性复合中心数目减少。
X-ray diffraction and photoluminescence technique are used to study the quality of undoped GaN films with different thickness. The densities of edge and screw dislocations and the strain of C axis are calculated with FWHM value of XRD rocking curve and position of diffraction peak respectively. The results show that with the increase of thickness, TD (Threading dislocation) and the strain are reduced, but the intensities of band to band and blue luminescence are enhanced. The mechanism of TD decrease is due to mergence and annihilation of dislocations in the growth of material. The enhancement of band to band and blue band luminescence may be result from the decrease of the centers of non-radiation recombination.
出处
《电子器件》
EI
CAS
2005年第2期262-264,共3页
Chinese Journal of Electron Devices
基金
国家重大基础研究(973)项目支持研究(51327020301)
