The effect of current crowding on the heat and light pattern in high-power AlGaAs light emitting diodes

The results of the light and temperature micromapping in AlGaAs light emitting diodes grown by
liquid phase epitaxy as double heterostructures and emitting at ��0.87 �m are presented. At a
driving current well above the safe operating limit ��300 mA�, the nonuniform light pattern and
local self-heating �with temperature gradient of about 950 °C/cm� followed by catastrophic
degradation of a device were detected with the charge coupled device and infrared microscopes
operating in a pulsed mode. These were shown to result from the current crowding effect in the active and contact areas of a device. Good agreement between the theory and experiment was found