Erasing the efficiency droop in cubic phase InGaAlN QW light-emitting diode

The inherent causes of the efficiency droop and low current density at the onset of the efficiency droop in green hexagonal-LEDs (h-LEDs) and cubic-phase InGaAlN LEDs (c-LEDs) are investigated with a new Open Boundary Quantum LED Simulator (OBQ-LEDsim). The coexistence of strong internal polarization and large carrier (i.e. electron and hole) effective mass induces strong Auger recombination that causes the large performance rollover in h-LEDs. On the opposite, in c-LEDs, the absence of internal polarization together with smaller carrier effective mass weakens Auger recombination, which quenches the droop by ~51%. These findings point at new ways to improve the performances of green LEDs.