Analysis of the External Quantum Efficiency of 233 nm Far‐Ultraviolet‐C‐Light Emitting Diodes with Distributed Polarization Doped <i>p</i> ‐AlGaN‐Layers

AlGaN‐based far‐ultraviolet‐C light emitting diodes (far‐UVC LEDs) with an emission wavelength of 233 nm and a peak external quantum efficiency () of 1% are explored to derive the radiative recombination efficiency (), the light extraction efficiency (), and the carrier injection efficiency (). In order to investigate the over a wide range of current density, and exclude the effect of heating, continuous wave and pulsed electroluminescence measurements are performed on far‐UVC LEDs with distributed polarization doped p ‐AlGaN layers. By applying the ABC‐model based Titkov–Dai method and calibrated Monte Carlo ray‐tracing simulations, a maximum of , a , and a can be determined. The different efficiency parameters of the 233 nm far‐UVC LEDs are compared to state‐of‐the‐art AlGaN‐based 265 nm LEDs and InGaN multi quantum well blue LEDs. In this context, strategies for most promising approaches to advance the of far‐UVC LEDs are discussed.