采用MOCVD技术在图形化硅衬底上生长了InGaN/GaN多量子阱黄光LED外延材料,研究了不同的量子阱生长气压对黄光LED光电性能的影响。使用高分辨率X射线衍射仪(HRXRD)和荧光显微镜(FL)对晶体质量进行了表征,使用电致发光系统积分球测试对光...采用MOCVD技术在图形化硅衬底上生长了InGaN/GaN多量子阱黄光LED外延材料,研究了不同的量子阱生长气压对黄光LED光电性能的影响。使用高分辨率X射线衍射仪(HRXRD)和荧光显微镜(FL)对晶体质量进行了表征,使用电致发光系统积分球测试对光电性能进行了表征。结果表明:随着气压升高,In的并入量略有降低且均匀性更好,量子阱中的点缺陷数目降低,但是阱垒间界面质量有所下降。在实验选取的4个气压4,6.65,10,13.3 k Pa下,外量子效率最大值随着量子阱生长气压的上升而显著升高,分别为16.60%、23.07%、26.40%、27.66%,但是13.3 k Pa下生长的样品在大电流下EQE随电流droop效应有所加剧,在20 A·cm-2的工作电流下,样品A、B、C、D的EQE分别为16.60%、19.77%、20.03%、19.45%,10 k Pa下生长的量子阱的整体光电性能最好。展开更多
Crack free GaN films were grown on 1200×1200𝜈m^(2) patterned Si(111)substrates and 36 light emitting diodes(LEDs)were fabricated in each pattern unit.Spatial distribution of the tensile stress in the patt...Crack free GaN films were grown on 1200×1200𝜈m^(2) patterned Si(111)substrates and 36 light emitting diodes(LEDs)were fabricated in each pattern unit.Spatial distribution of the tensile stress in the pattern units and its influence on the LED performance are studied by micro-Raman and electroluminescence(EL).The Raman shift of the GaN𝐹E_(2) mode shows that the tensile stress is the maximum at the center,partially relaxed at the edge,and further relaxed at the corner.With the stress relaxation,the EL wavelength has a significant blue shift and the luminous intensity shows a great enhancement.展开更多
文摘采用MOCVD技术在图形化硅衬底上生长了InGaN/GaN多量子阱黄光LED外延材料,研究了不同的量子阱生长气压对黄光LED光电性能的影响。使用高分辨率X射线衍射仪(HRXRD)和荧光显微镜(FL)对晶体质量进行了表征,使用电致发光系统积分球测试对光电性能进行了表征。结果表明:随着气压升高,In的并入量略有降低且均匀性更好,量子阱中的点缺陷数目降低,但是阱垒间界面质量有所下降。在实验选取的4个气压4,6.65,10,13.3 k Pa下,外量子效率最大值随着量子阱生长气压的上升而显著升高,分别为16.60%、23.07%、26.40%、27.66%,但是13.3 k Pa下生长的样品在大电流下EQE随电流droop效应有所加剧,在20 A·cm-2的工作电流下,样品A、B、C、D的EQE分别为16.60%、19.77%、20.03%、19.45%,10 k Pa下生长的量子阱的整体光电性能最好。
基金Supported by the National High-Technology Research and Development Program of China under Grant No 2011AA03A101the National Natural Science Foundation of China under Grant No 51072076the National Key Technology Research and Development Program of China under Grant No 2011BAE32B01.
文摘Crack free GaN films were grown on 1200×1200𝜈m^(2) patterned Si(111)substrates and 36 light emitting diodes(LEDs)were fabricated in each pattern unit.Spatial distribution of the tensile stress in the pattern units and its influence on the LED performance are studied by micro-Raman and electroluminescence(EL).The Raman shift of the GaN𝐹E_(2) mode shows that the tensile stress is the maximum at the center,partially relaxed at the edge,and further relaxed at the corner.With the stress relaxation,the EL wavelength has a significant blue shift and the luminous intensity shows a great enhancement.
