Design and Optimization of Electron-Blocking Layer in Deep Ultraviolet Light-Emitting Diodes

Optical and electrical performance and the relevant physical properties of deep ultraviolet (DUV) AlGaN-based light-emitting diodes (LEDs) are numerically investigated. The influence of bulk AlGaN electron-blocking layer (EBL) with various Al compositions and Mg-doping concentrations on the output performance of DUV LEDs is systemically explored. Simulation results show that the DUV LED with bulk Al
_0.85
Ga
_0.15
N EBL with a relatively low Mg-doping concentration of 2×10
¹⁹
cm
^-3
may have high wall-plug efficiency. The LED structure with Al
_0.55
Ga
_0.45
N/Al
_0.75
Ga
_0.25
N superlattice (SL) EBL is proposed in this study, which is shown to have high wall-plug efficiency similar to the LED with bulk Al
_0.85
Ga
_0.15
N EBL while the Al composition of AlGaN EBL can be effectively reduced. The proposed LED structure with SL EBL provides a practical way to fabricate high-crystalline-quality and high-efficiency DUV LEDs.