AlGaN-Based Deep UV Laser Diodes without an Electron Blocking Layer and with a Reduced Aluminum Composition of Quantum Barriers

An electron blocking layer (EBL) is often utilized in the p-type region of AlGaN-based deep ultraviolet laser diodes (DUV LDs) to control electron overflow. However, Al-rich semiconductor DUV LD EBLs can be difficult to p-doping and have a highly-complicated structure. Furthermore, the composition of Al in quantum barriers (QBs) of multiple quantum wells (MQWs) affects the performance of AlGaN-based DUV laser diodes. Omitting the EBL and reducing the Al content of the QBs can enhance the optical confinement and optical output power. Observing the performance parameters, such as the optical confinement factor (OCF), emitted power, band diagram, carrier concentration, and stimulated recombination, may be an effective way to monitor these changes. In this paper, using the crosslight software LASTIP, we simulate and compare three DUV LD devices with a nominal wavelength of 267.5 nm. In contrast to the reference DUV LD with a p-type EBL, the proposed EBL-free DUV LD with reduced Al-composition QBs is applied in MQWs; this results in a 21% improvement in the OCF and an increase in the output power.