Evolution of stress relaxation and yellow luminescence in GaN/sapphire by Si incorporation
Evolution of stress relaxation and yellow luminescence in GaN/sapphire by Si incorporation
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DOI：
10.1063/1.119893
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发表时间：
1997-09
影响因子：
4
通讯作者：
In‐Hwan Lee;I. Choi;Cheul‐Ro Lee;S. Noh
中科院分区：
文献类型：
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作者：
In‐Hwan Lee;I. Choi;Cheul‐Ro Lee;S. Noh
我们报道了一系列在蓝宝石（0001）上生长的未掺杂和Si掺杂的GaN外延层的系统研究，载流子浓度为4.0×1017 - 1.6×1019 cm-3，以研究Si掺入引起的应力弛豫和黄光发光的演变。随着Si掺杂量的增加，由于热残余应力的松弛，束缚激子峰逐渐向低能方向移动，线性系数为ΔE/Δσ ε =42 meV/GPa。结果表明，随着Si掺杂量的增加，双晶X射线衍射半峰全宽和黄光与边光的发光强度比逐渐增大。我们认为Si掺杂GaN外延层中引入了整体缺陷，并在冷却过程中引起应力弛豫，而黄色发光可能源于VGa和Si诱导缺陷的复合物。
We report a systematic study accomplished with a series of undoped and Si-doped GaN epilayers grown on sapphire (0001) with the carrier concentration of 4.0×1017−1.6×1019 cm−3 in order to investigate the evolution of stress relaxation and yellow luminescence by Si incorporation. As the Si doping becomes higher, the bound exciton peaks are gradually shifted to lower energy due to relaxation of the thermal residual stress with the linear coefficient of ΔE/Δσ∥=42 meV/GPa. The present results show that both the full width at half maximum of double-crystal x-ray diffractometry and the photoluminescence intensity ratio of the yellow luminescence to edge emission gradually increase as the Si incorporation becomes heavier. We suggest that the Si doping in GaN epilayers induces overall defects and gives rise to stress relaxation during the cool-down process, and the yellow luminescence may be originated from a complex of VGa and the Si-induced defect.