Localized and quantum-well state excitons in AlInGaN laser-diode structure

Two emission peaks with different behaviors are observed from the electroluminescence spectrum of AlInGaN laser diode structure. A significant blueshift and a linewidth broadening are measured for the low-energy peak with an injection current, while a slight blueshift and a moderate linewidth narrowing occur for the high-energy peak. Accordingly, these two peaks are assigned to be from localized state and quantum well state emissions, respectively. The quantum well state emission exhibits a biexciton feature in contrast to the localized excitons. Based on the injection current dependent thermal quenching behavior of the localized state, a multiple carrier escaping mechanism is proposed.