Design of Asymmetric Quantum Barrier for Deep-Ultraviolet Light-Emitting Diode With High Crystal Quality

In this study, impacts of quantum barrier (QB) width on the device performance of deep-ultraviolet (DUV) light-emitting diode (LED) are investigated theoretically under different crystal quality. Simulation results show that, in comparison with the first QB and middle QBs, the last QB (LQB) plays a much more important role in DUV LEDs. Specifically, the capability of electron confinement and relevant electron current leakage are critically affected by the thickness of LQB, especially at a high degree of polarization or with high crystalline quality. Furthermore, if a DUV LED is with a thin LQB, e.g., 3-nm-thick LQB, the light output power and wall-plug efficiency (WPE) can be maintained relatively high under the situation of either low or high degree of polarization. Thin LQB is thus favorable for the DUV LEDs with high crystalline quality due to the good confinement capability under a high degree of polarization.