High-Efficiency Deep Ultraviolet Light-Emitting Diodes without an Electron Blocking Layer Enabled by a High-Aluminum-Content Spanning Superlattice p-Type Region

Deep ultraviolet light-emitting diodes (DUV-LEDs) face critical challenges such as poor hole injection and significant electron leakage, both of which severely limit their external quantum efficiency (EQE). This study possesses and simulates six DUV-LED structures featuring p-type superlattices with varying aluminum compositions using the SiLENSe module that integrates Schrödinger-Poisson and drift-diffusion models. Among them, structure F, which eliminates the conventional electron blocking layer (EBL) and incorporates a graded Al_0.8Ga_0.2N/Al_0.6Ga_0.4N superlattice, demonstrates the best performance. It achieves an EQE of 6.3% and a peak optical output power of 25 mW. Detailed analyses of band diagrams and carrier distributions confirm that the structure simultaneously enhances hole injection and effectively suppresses electron leakage. These improvements are attributed to the formation of stepped valence band profiles and reinforced electron barriers within the superlattice. This dual-function design highlights a viable and efficient strategy for advancing high-performance DUV-LEDs through p-type band engineering without relying on traditional EBLs.