Effect of Mg doping concentration of electron blocking layer on the performance of GaN-based laser diodes

Performance of InGaN-based laser diodes (LDs) with different Mg concentrations of electron blocking layer (EBL) is investigated by simulation and experimental methods. It is found from the simulation results that the threshold current decreases and slope efficiency increases, when the Mg concentration of EBL increases from 2 × 1018 to 6 × 1019 cm−3; it is attributed to the suppression of the leakage of electrons and the enhancement of the injection of holes due to the variation of potential barrier for them as the increase of Mg concentration of EBL. These simulation results agree well with the experimental ones, when the Mg concentration of EBL is lower than 7.5 × 1018 cm−3. However, it deteriorates when the Mg concentration increases to 1.2 × 1019 cm−3. It may be due to the increase of the absorption loss of LDs.