AlGaN-based germicidal UV LEDs show promise in fighting the COVID-19 pandemic through disinfection of air, water, and surfaces. We report UV LEDs grown by MOCVD on SiC substrates, fabricated into thin-film flip chip devices. Replacing the uniform p-AlxGa1-xN layer (x = 0.2) with a short-period-superlattice of alternating (x = 0.1 and 0.8) Al-composition improved EQE from 1.3% to 2.7% (3.2% with encapsulation) at 20 A/cm2. Peak EQE and WPE values of 4.8% and 2.8% (287 nm) were measured at current densities below 2 A/cm2, and maximum output power of 7.4 mW (76 mW/mm2) was achieved at 284 nm. Further WPE improvements are expected with both superlattice and uniform layer optimization, improved p-contact metallization, and active region optimization.

中文翻译：

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用于在 SiC 上生长的 UV LED 的超晶格空穴注入层

基于 AlGaN 的杀菌 UV LED 有望通过对空气、水和表面进行消毒来对抗 COVID-19 大流行。我们报告了通过 MOCVD 在 SiC 衬底上生长的 UV LED，制造成薄膜倒装芯片器件。用交替（x = 0.1 和 0.8）Al 成分的短周期超晶格替换均匀的 p-AlxGa1-xN 层（x = 0.2），在 20 A 下将 EQE 从 1.3% 提高到 2.7%（封装为 3.2%） /cm2。在低于 2 A/cm2 的电流密度下测得的峰值 EQE 和 WPE 值为 4.8% 和 2.8% (287 nm)，在 284 nm 处实现了 7.4 mW (76 mW/mm2) 的最大输出功率。通过超晶格和均匀层优化、改进的 p 接触金属化和有源区优化，预计 WPE 会进一步改进。