Enhancing the performance of high-power DUV-LEDs with sloped sidewall by introducing N-electrode holes and interrupted mesa.

This study introduces innovative structural enhancements in deep ultraviolet LEDs (DUV-LEDs) to optimize Performance. By implementing a 46.9° sloped mesa sidewall, we have designed what we believe to be two novel structures: an n-electrode hole structure that extends the active region and an interrupted mesa structure that significantly enlarges the sidewall area. We investigated the effects of these structures on DUV-LED performance independently and demonstrated that both single structure devices surpass the performance of conventional DUV-LEDs. Notably, the interrupted mesa structure yields a more substantial performance enhancement at higher injection currents, while the n-electrode hole structure excels at lower currents. Meanwhile, this paper also prepared two kinds of DUV-LEDs with parallel and staggered rows of mesa and n-electrode holes by combining the above two single structures on the same device. Compared with the single structure device, the performance of these combined structure devices is further improved, in which the performance of the DUV-LEDs with staggered rows of mesa and n-electrode holes is even better, the external quantum efficiency (EQE) and wall plug efficiency (WPE) of 9.19% and 7.13% at 250 mA operating current, which is an improvement of 9.6% and 4.4%, respectively, compared with that of the conventional DUV-LEDs. Furthermore, the enhancement in performance will be augmented with an increase in current, due to the efficient conversion of active area to sidewall area. At 500 mA, the optical power of the staggered-array device is increased by 10.6% compared to conventional DUV-LEDs; at 1000 mA, the optical power is increased by 17.7%.