Internal quantum efficiency of GaN-based light-emitting diodes grown on silicon substrates determined from rate equation analyses

• We develop a convenient and reliable method for determining the IQE of LEDs.
• The IQE model was successfully applied to InGaN blue LEDs on Si substrates.
• High IQE of ∼0.74 is obtained from the blue LED grown on Si substrates.
• The obtained IQE agrees well with that obtained by the conventional TDPL method.

We present a convenient and reliable method for determining the internal quantum efficiency (IQE) in GaN-based blue light-emitting diodes (LEDs) grown on Si(111) substrates based on the carrier rate equation model. By using the peak point of the efficiency curve in photoluminescence (PL) measurements as the parameter of the rate equation analysis, the IQE can be unambiguously determined without any pre-assumed parameters. The theoretical IQE model is used to fit the measured PL efficiency curves and the IQE of LED samples are determined. The maximum IQE of the LED sample grown on the Si substrate was obtained to be 0.74, which is found to agree well with the results obtained by conventional temperature-dependent PL measurements.