Low pressure MOCVD has been used to investigate the properties of low temperature buffer layer deposition conditions and their influence on the properties of high temperature GaN epilayers grown subsequently. It is fo...Low pressure MOCVD has been used to investigate the properties of low temperature buffer layer deposition conditions and their influence on the properties of high temperature GaN epilayers grown subsequently. It is found that the surface morphology of the as grown buffer layer after thermal annealing at 1 030 ℃ and 1 050 ℃ depends strongly on the thickness of the buffer layer. In particular when a thick buffer layer is used, large trapezoidal nuclei are formed after annealing.展开更多
Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer has been studied by means of photoluminescence spectroscopy and high resolution X-ray diffraction.It is ...Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer has been studied by means of photoluminescence spectroscopy and high resolution X-ray diffraction.It is found that the densities of screw and edge threading dislocations increase with the V/III ratio of the buffer layer,and the intensities of the yellow luminescence(YL) and blue luminescence(BL) emissions also increase dramatically.However,the density ratio of the edge threading dislocation to the screw threading dislocation remains invariant,as well as the intensity ratio of YL emission to BL emission.It can be concluded from these phenomena that the edge threading dislocation and screw threading dislocation can enhance the YL and BL emissions,respectively.展开更多
文摘Low pressure MOCVD has been used to investigate the properties of low temperature buffer layer deposition conditions and their influence on the properties of high temperature GaN epilayers grown subsequently. It is found that the surface morphology of the as grown buffer layer after thermal annealing at 1 030 ℃ and 1 050 ℃ depends strongly on the thickness of the buffer layer. In particular when a thick buffer layer is used, large trapezoidal nuclei are formed after annealing.
基金supported by the Special Funds for Major State Basic Research Project (Grant Nos.2011CB301900,2012CB619304,and 2012CB619200)the Hi-tech Research Project (Grant No.2011AA03A103)+4 种基金the National Natural Science Foundation of China (Grant Nos.60990311,60820106003,60906025,60936004,and 61176063)the Natural Science Foundation of Jiangsu Province (Grant Nos.BK2008019,BK2011010,BK2010385,BK2009255,and BK2010178)the Program Granted for Scientific Innovation Research of College Graduate in Jiangsu Province (Grant No.CXLX12_0049)the Research Funds from NJU-Yangzhou Institute of Opto-electronicsa project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer has been studied by means of photoluminescence spectroscopy and high resolution X-ray diffraction.It is found that the densities of screw and edge threading dislocations increase with the V/III ratio of the buffer layer,and the intensities of the yellow luminescence(YL) and blue luminescence(BL) emissions also increase dramatically.However,the density ratio of the edge threading dislocation to the screw threading dislocation remains invariant,as well as the intensity ratio of YL emission to BL emission.It can be concluded from these phenomena that the edge threading dislocation and screw threading dislocation can enhance the YL and BL emissions,respectively.
