Heteroepitaxy of AlGaN on bulk AlN substrates for deep ultraviolet light emitting diodes
Heteroepitaxy of AlGaN on bulk AlN substrates for deep ultraviolet light emitting diodes
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DOI：
10.1063/1.2766841
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发表时间：
2007-08
影响因子：
4
通讯作者：
Z. Ren;Qian Sun;Suk-Dong Kwon;Jung Han;K. Davitt;Yoon-Kyu Song;A. Nurmikko;H. Cho;Wayne Liu-Wayn
中科院分区：
文献类型：
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作者：
Z. Ren;Qian Sun;Suk-Dong Kwon;Jung Han;K. Davitt;Yoon-Kyu Song;A. Nurmikko;H. Cho;Wayne Liu-Wayn
作者报道了在大块AlN衬底上生长AlGaN涂层和深紫外发光二极管（led）。通过控制生长中断研究了异质外延成核和应变松弛。由于AlN块体中预先存在的位错密度较低，使得AlGaN异质外延过程中的压缩应变不能得到有效的缓解。应变能的积累最终通过位错的产生和倾斜导致弹性表面粗糙化或塑性变形，这取决于所使用的应力源夹层和生长参数。大块AlN上的AlGaN led比蓝宝石上的AlGaN led表现出明显的性能改善，这为iii -氮化物紫外光电子学提供了一个有前途的衬底平台。
The authors report the growth of AlGaN epilayers and deep ultraviolet (UV) light emitting diodes (LEDs) on bulk AlN substrates. Heteroepitaxial nucleation and strain relaxation are studied through controlled growth interruptions. Due to a low density of preexisting dislocations in bulk AlN, the compressive strain during AlGaN heteroepitaxy cannot be relieved effectively. The built-up of strain energy eventually induces either an elastic surface roughening or plastic deformation via generation and inclination of dislocations, depending on the stressor interlayers and growth parameters used. AlGaN LEDs on bulk AlN exhibit noticeable improvements in performance over those on sapphire, pointing to a promising substrate platform for III-nitride UV optoelectronics.