230 nm wavelength range far-UVC LED with low Al-composition differentiation between well and barrier layers of MQWs

Abstract

Reducing the average Al composition of Al _x Ga _1− _x N/Al _y Ga _1− _y N multiple quantum wells (MQWs) is an effective approach to increase the current injection efficiencies of far-UV-C LEDs (far-UVC LEDs). A reduction can be realized by decreasing the Al-composition differentiation between the well and barrier layers. Compared to conventional MQWs, a 230 nm wavelength far-UVC LED equipped with a single-Al-composition and a 39 nm thick light-emitting layer exhibits a higher external quantum efficiency (EQE). The EQE of far-UVC LEDs with low Al-composition differentiation (∼1%) is enhanced to approximately 0.6% and 1.4% under continuous wave operations at 230 nm and 236 nm wavelengths, respectively.

Keywords

• LED
• far-UVC
• AlGaN
• face-to-face annealed sputter-deposited AlN template