Efficiency droop contributors in InGaN green light emitting diodes

Here, efficiency droop contributors (i.e., inherent Auger-Meitner recombination, polarization-induced effects, thermal effects, and light extraction) in InGaN green light emitting diodes (LEDs) are decoupled and quantified. First, a modified ABC model is developed, and external quantum efficiency measurements are taken under constant and pulsed currents ( EQE Constant and EQE Pulsed , respectively). The LED internal quantum efficiency with and without thermal effects ( IQ E Constant ABC and IQ E Pulsed ABC , respectively) is extracted using the modified model. Then, using Raman spectroscopy, the LED junction temperature is extracted. Finally, using the optical-electrical model (OEM), the polarization- and temperature-independent LED internal quantum efficiency ( IQE OEM ) is calculated from the modified ABC model and the extracted junction temperature. By comparing external ( EQE Constant ) and the three internal quantum efficiencies ( IQ E Constant ABC , IQ E Pulsed ABC , and IQE OEM ), the impacts of inherent Auger-Meitner recombination, polarization-induced effects, thermal effects, and light extraction on the efficiency droop are decoupled and quantified. It is found that inherent Auger-Meitner recombination-induced droop is approximately 49% of the total efficiency droop in commercial green LEDs, while polarization-induced effects contribute about 35%, and thermal droop accounts for nearly 16%. These findings suggest, to quash the green gap, it is critical to search for materials and device designs with low inherent Auger-Meitner coefficients and polarization fields, respectively.