The effect of diode area on the luminescence of InGaN quantum well light emitting diodes grown by MOCVD

The effect of LED size on the light output and quantum efficiency was studied. The diodes showed evidence of a parasitic nonradiative current path at low DC currents which saturated at higher current levels. Under DC current the efficiency of the LEDs decreases before reaching a constant value, whereas under pulsed testing the LEDs reached a constant quantum efficiency. The effect of the nonradiative current path is reduced under pulsed operation which indicates that the nonradiative current path is due to heating. The heating dominates the power output and efficiency at high DC current levels. This heating effect is more severe for larger devices due to a smaller perimeter to area ratio compared to smaller devices.