应变补偿InGaN/AlGaN超晶格改善近紫外LED性能

摘要

通过应变平衡理论设计出应变补偿的In0.1Ga0.9N/Al0.2Ga0.8N超晶格结构。为了验证该结构具有低的应变，实验生长了相应的样品，并通过双晶衍射（XRD）和拉曼（Raman）光谱实验证实其具有低应力。最后把该结构用于近紫外LED的两处构建，一是替代量子阱中的GaN垒层，二是作p型层的接触层。实验发现，该结构的应用不但可以减弱量子阱的Stark效应和抑制电子泄露，而且降低p型接触层的欧姆接触电阻。且发现不用电子阻挡层情况下，其输出功率、PL光谱和I-V特性等都得到极大改善。%The strain-compensated In0.1Ga0.9N/Al0.2Ga0.8N superlattice structure was designed by strain equilibrium theory. To verify the structure with low stress, p-InGaN/p-AlGaN superlattice lattice layers (SLs) with a strain-compensated structure was fabricated by epitaxial growth technology, and low stress in the structure was verified by double-crystal x-ray diffraction (XRD) and Raman spectroscopy (Raman). The experimental results show that the near-UV LEDs with strain-compensated In0.1Ga0.9N/Al0.2Ga0.8N SLs have higher emission power over their conventional counterparts with GaN barriers due to the mitigation of the quantum-confined Stark effect and the suppression of electron leakage. Furthermore, the performances of the near-UV LEDs with proposed InGaN/AlGaN barriers can be further improved without electron blocking layers.