Reverse compositional strategy of multiple quantum wells for the AlGaN-based deep-ultraviolet laser diodes

Abstract

Due to the high activation energy/ionization energy as Mg increases, Al-rich AlGaN-based deep-ultraviolet (DUV) laser diodes have a structure that is difficult to perform Mg p-doping. The performance of this type of laser diode is affected by the content of Al in the quantum barriers of multiple quantum wells, and reducing the Al content in the laser diodes may simplify its structure and make Mg p-doping less difficult. The proposed device can be improved by adopting the reverse compositional strategy of multiple quantum wells with the Al content of quantum barriers 10% lower than that of quantum wells as opposed to the reference device where the Al content of the quantum barriers is 10% higher than that of the quantum wells. The simulation results have been observed theoretically in terms of the performance parameters such as band diagrams, optical confinement factor, peak gain, emitted power, stimulated recombination rate, and carrier concentration. Two deep ultraviolet laser diode devices have been analyzed in this study within the wavelength range of 267 nm. The proposed device has superior performance with a larger optical confinement factor and increased output power with reduced injection current.