Temperature Dependence of the Component Currents and Internal Quantum Efficiency in Blue Light-Emitting Diodes

We have decomposed the blue light-emitting diode (LED) current into the constituent components and studied the temperature dependence of each component and the internal quantum efficiency (IQE) quantitatively over the temperature range from 0°C to 80°C. The most temperature-sensitive current component is the nonradiative recombination current that increases with the temperature rise, and the component plays a dominant role in determining the temperature dependence of the IQE and luminescence output. Therefore, high-efficiency LEDs achieve high power and low temperature sensitivity simultaneously. On the other hand, the portion of the loss current that is responsible for the efficiency droop decreases with the temperature rise, resulting in lower droop at higher temperature. Some consequences and implications of the temperature dependence are also discussed.