230 nm wavelength range far-UVC LED with low Al-composition differentiation between well and barrier layers of MQWs
Kenjiro Uesugi, Ryota Akaike, Shuhei Ichikawa, Takao Nakamura, Kazunobu Kojima, Masahiko Tsuchiya, Hideto Miyake
Abstract
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.