摘要
We report the structural and optical properties of nonpolar m-plane GaN and GaN-based LEDs grown by MOCVD on a 7-LiAlO2 （100） substrate. The TMGa, TMIn and NH3 are used as sources of Ga, In and N, respectively. The structural and surface properties of the epilayers are characterized by x-ray diffraction, polarized Raman scattering and atomic force microscopy （AFM）. The films have a very smooth surface with rms roughness as low as 2nm for an area of 10×10μm^2 by AFM scan area. The XRD spectra show that the materials grown on 7-LiAl02 （100） have （1 - 100） m-plane orientation. The EL spectra of the m-plane InGaN/GaN multiple quantum wells LEDs are shown. This demonstrates that our nonpolar LED structure grown on the 7-LiAlO2 substrate is indeed free of internal electric field. The current voltage characteristics of these LEDs show the rectifying behaviour with a turn on voltage of 1-3 V.
We report the structural and optical properties of nonpolar m-plane GaN and GaN-based LEDs grown by MOCVD on a 7-LiAlO2 （100） substrate. The TMGa, TMIn and NH3 are used as sources of Ga, In and N, respectively. The structural and surface properties of the epilayers are characterized by x-ray diffraction, polarized Raman scattering and atomic force microscopy （AFM）. The films have a very smooth surface with rms roughness as low as 2nm for an area of 10×10μm^2 by AFM scan area. The XRD spectra show that the materials grown on 7-LiAl02 （100） have （1 - 100） m-plane orientation. The EL spectra of the m-plane InGaN/GaN multiple quantum wells LEDs are shown. This demonstrates that our nonpolar LED structure grown on the 7-LiAlO2 substrate is indeed free of internal electric field. The current voltage characteristics of these LEDs show the rectifying behaviour with a turn on voltage of 1-3 V.
基金
The National Basic Research Programme of China under Grant No 2006CB6049, the National High-Tech Research and Development Programme of China under Grant Nos 2006AA03A103, 2006AA03Al18, 2006AA03A142, the National Natural Science Foundation of China under Grant Nos 60390072, 60676057, 60421003, The Research Fund for the Doctoral Programme of Higher Education of China （20050284004）
