Understanding carrier dynamics in GaN-based blue light-emitting diodes by self-consistent analysis of current, voltage, internal quantum efficiency, and forward capacitance

A self-consistent analysis of current, voltage, internal-quantum efficiency, and forward capacitance of the GaN-based blue light-emitting diode (LED) is presented to obtain the detailed information on the carrier dynamics inside and outside the active quantum well (QW). In the analysis, the forward capacitance of the device plays a crucial role in providing additional information on the region where the nonradiative recombination occurs. The experimental data from a GaN-based blue LED are used in the analysis to show how charge carriers distribute inside and outside the QW and how carrier lifetimes and radiative/nonradiative currents behave as functions of applied voltage and current. It is shown that charge carriers recombine in the well with an-order-of-magnitude-higher density than in the barrier/interlayer.