High-Efficiency E-Beam Pumped Deep-Ultraviolet Surface Emitter Based on AlGaN Ultra-Thin Staggered Quantum Wells

A 2-inch wafer-scale electron-beam (e-beam) pumped deep-ultraviolet surface emitter (DUVSE) with high efficiency and high output power at an emission wavelength of 248 nm is reported. This DUVSE benefits from ultra-thin staggered AlN/AlGaN/GaN multiple quantum wells (MQWs), which compromise the electron-hole overlap and carrier confinement and thus significantly improve the emission efficiency. The wall-plug-efficiency (WPE) is increased by six times to 5.25% in comparison to that of conventional DUV light-emitting devices (LEDs) based on AlGaN MQWs. This WPE is achieved under an anode voltage and current of 8 kV and 1 mA, where the output power is 420 mW. This output power can be further enhanced to 702 mW by increasing the anode current to 3 mA. The enhanced WPE and uniform electron beam distribution lighten the avenue to achieve a wafer-scale high power dense DUV light source, which is a challenge for conventional DUV-LEDs, in particular with an emission wavelength of less than 250 nm.