Increased Radiative Recombination in Nitride Laser Diodes with Inverse Tapered Electron Blocking Layer

Abstract

A deep ultraviolet laser structure was proposed, which can lase at 261 nm band. In this simulation, the width of this laser diode was set to 4 $\mu$m and the cavity length was set to 530 $\mu$m. The mirror reflective index and the background loss were set to 0.05 and 2400, respectively. All the characteristics of the deep-UV laser diode were simulated under room temperature. The tapered EBL (electron bl1ocking layer), the inverse tapered EBL and the reference EBL were applied to this laser. When the tapered EBL is replaced by the inverse tapered EBL, the effective potential height of the EBL increased from 532 meV to 610 meV. This improvement means higher electronic blocking ability. More electrons will be confined to the active layer. Compared with the reference EBL, the electron leakage of inverse tapered EBL reduced about 22.7%. The concentration of carriers in the active layer is simulated. The radiative concentration increased by 1.48% for the inverse tapered EBL. The promotion of the radiative concentration indicated higher laser’s output power. The inverse tapered EBL is a far-reaching structure for laser diodes.