摘要
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Al_(0.19)Ga_(0.81)N/Al_(0.37)Ga_(0.63)N 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 Al_(0. 19)Ga_(0. 81)N/Al_(0. 37)Ga_(0. 63) N DBRs were grown on n-type 6H-SiC substrates by metal organic chemical vapor deposition( MOCVD). To suppress the generation of cracks,a lowtemperature 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.
引文
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