Multiquantum well design and carrier transport of AlGaN-based far-UVC LEDs with emission wavelengths between 225 nm and 233 nm

The effect of the active region design of far-UVC LEDs with emission between 225 nm and 233 nm was investigated. Increasing the number of quantum wells (QWs) resulted in a positive correlation between lifetime and initial output power. Carrier transport was studied by incorporating a QW with emission at 250 nm close to the n-side of 233 nm far-UVC LEDs. For far-UVC LEDs with emission at 225 nm the multi-quantum well (MQW) was compared to a single Al0.85Ga0.15N layer with varied thickness and doping level to investigate the influence on output power, efficiency, and lifetime. To enhance hole injection into the active region of far UVC LEDs linearly graded (from AlN to AlxGa1-xN) distributed polarization doped layers were grown.