Internal quantum efficiency and carrier injection efficiency ofc-plane, {101‾1} and {112‾2} InGaN/GaN-based light-emitting diodes

The electroluminescence (EL) output power of c-plane InGaN/GaN-based light-emitting diodes (LEDs) is much higher than that of semipolar and LEDs at the same operation current. In order to elucidate the reasons for this behavior, we have fitted the pulsed EL data by the well-known ABC model to extract the internal quantum efficiency (IQE) and the carrier injection efficiency (CIE) to clarify which parameter weighs more for the poor EL output power of the semipolar LEDs. The CIE shows large differences, 78%, 4%, and 4% for the c-plane, and LEDs, respectively, whereas the IQE values are fairly the same for all three structures. The fit of resonant photoluminescence (PL) data at room temperature confirms the similar IQE values for all three structures. The CIE was increased from 4% to 10% for the planar LED with better electrical conductivity of the p-GaN layer.