Evaluation of the temperature-dependent internal quantum efficiency and the light-extraction efficiency in a GaN-based blue light-emitting diode by using a rate equation model

The internal quantum efficiency (IQE) and the light extraction efficiency (LEE) of a GaN-based blue light-emitting diode (LED) are evaluated separately in the temperature range between 20 to 80 °C. The theoretical IQE model based on the carrier rate equation of semiconductors is applied to determine the IQE and the LEE separately from a measured external quantum efficiency (EQE) versus current relation for the LED sample. While the peak EQE of the measured sample decreases by 3.2 % as the temperature increases from 20 to 80 °C, it is found that the peak IQE decreases by 4.5 % and the LEE increases by 1.5 %.