Temperature Dependence of Efficiency in GaInN/GaN Light-Emitting Diodes with a GaInN Underlayer

The temperature dependence of the efficiency (i.e., temperature-mediated efficiency droop) in blue light-emitting diodes (LEDs) is investigated. A GaInN/GaN LED with a GaInN underlayer having an indium mole fraction of 8% shows less temperature dependence of efficiency, compared to the LED without an underlayer. Better carrier confinement in the active region of the LED with a GaInN underlayer is proposed to reduce carrier leakage from the active region at high temperature. The results indicate that the insertion of an underlayer leads to an improvement of the LED's radiative efficiency and its high-temperature-tolerant performance.