Interference effect in deep-ultraviolet light emitting diodes with p-AlGaN contact layers and ITO/Al electrodes

We investigated light output power (LOP) values of AlGaN-based deep ultraviolet LEDs with transparent $\mathrm{p}^{+}$ -AlGaN contact layers and inexpensive ITO/Al electrodes as a function of p-layer thickness. The measured LOP values were increased as the p-layer thickness was decreased. This increase was due to the interference effect. Further reduction of the internal absorption could improve the LOP of the LEDs.