电子阻挡层对UV LED芯片老化后反向漏电的影响

着重对紫外(UV)LED芯片的反向漏电进行研究,使用高Al组分的AlGaN材料作为LED外延结构中的电子阻挡层(EBL),旨在解决UV LED芯片在老化后的漏电问题。结果表明,高Al组分的AlGaN EBL凭借其足够高的势垒高度,可以有效降低电子泄漏水平,从而改善UV LED芯片在老化后的反向漏电问题。选取365~415 nm波段、量子阱禁带宽度为3.0~3.4 eV的外延片为研究对象,研究了EBL工艺对老化后芯片漏电性能的影响,得到AlGaN EBL的最佳Al组分为30%~40%,对应禁带宽度为4.0~4.3 eV。使用该方法制作的UV LED芯片在经过长时间老化后,其漏电流可以保持在1 nA以下,综合性能大幅提升。

Influence of Electron Blocking Layer on Reverse Leakage of UV LED Chip After Aging

The reverse leakage of ultraviolet(UV)LED chips was emphatically studied.AlGaN material with high Al composition was used as the electron blocking layer(EBL)in the LED epitaxial structure to solve the problem of the leakage of UV LED chips after aging.The results show that the AlGaN EBL with high Al composition can effectively reduce the level of electron leakage by virtue of its sufficiently high barrier height,thereby improving the reverse leakage of UV LED chips after aging.The epitaxial wafer with wavelength of 365-415 nm and bandgap width of the quantum well of 3.0-3.4 eV was selected as the research object to study the influence of the EBL process on the leakage performance of the chip after aging.The optimal Al composition of the AlGaN EBL is 30%-40%,and the correspon-ding bandgap width is 4.0-4.3 eV.The leakage current of the UV LED chip produced by this method maintains below 1 nA after long-term aging,and the overall performance is greatly improved.