AlGaN-based 280nm light-emitting diodes with continuous-wave power exceeding 1mW at 25mA

Abstract

Optimization of the migration-enhanced metalorganic chemical vapor deposition and further optimization of the contact and active layer design for $280\mathrm{nm}$ light-emitting diodes resulted in large improvement of cw and pulsed output power and in a superior spectrum purity. The ratio of the main peak to the background luminescence determined by the detection system is higher than 2000:1 at $20\mathrm{mA}$ dc. The on-wafer cw power was measured to be $255\mu \mathrm{W}$ at $20\mathrm{mA}$ dc. The power popped up exceeding $1\mathrm{mW}$ for a packaged device under $25\mathrm{mA}$ dc and $9\mathrm{mW}$ under pulse $200\mathrm{mA}$ . The maximum wall-plug-efficiency of 0.67% was obtained for the packaged device at $25\mathrm{mA}$ dc.