利用金属有机物化学气相沉积方法, 在n型6H-SiC衬底上制备了15对Si掺杂Al0.19Ga0.81N/Al0.37Ga0.63N DBR, 并采用低温AlN缓冲层有效抑制了DBR结构中裂纹的产生, 得到了表面均方根粗糙度仅为0.4 nm且导电性能良好的n型DBR, 其在369 nm处峰值反射率为68%, 阻带宽度为10 nm。在获得导电DBR的基础上, 进一步在n型6H-SiC衬底上构建了有、无DBR的垂直结构紫外LED。对比两者电致发光光谱, 发现DBR结构的引入有效增强了LED紫外发光强度。

Silicon-doped Al0.19Ga0.81N/Al0.37Ga0.63N DBRs were grown on n-type 6H-SiC substrates by metal organic chemical vapor deposition(MOCVD). To suppress the generation of cracks, a low-temperature AlN pre-deposition layer on 6H-SiC(0001) substrate was used as buffer. A smooth-surface 15-pair electrically conducting DBR with a reflectance of 68% at 369 nm was obtained. The stop-band bandwidth and RMS value of DBR are 10 nm and 0.4 nm, respectively. Furthermore, the vertical structure UV LEDs with and without n-DBR on 6H-SiC substrate were fabricated. By comparing EL spectra, it is shown that the introduction of DBR structure can effectively improve the UV emission.