The paper investigates the efficiency droop in GaInN/GaN multiple-quantum well (MQW) light-emitting diodes (LEDs). It finds that the efficiency droop, which occurs under high injection conditions, is not related to junction temperature but rather to carrier recombination outside the MQW region. Photoluminescence measurements show no droop when excitation power is varied, indicating that the droop is not due to MQW efficiency but to carrier escape from the MQW region. Simulations reveal that polarization fields in the MQW and electron blocking layer (EBL) enable electron escape, leading to the droop. The authors demonstrate that using quaternary AlGaN compositions can reduce these polarization effects, minimizing droop and improving efficiency. The study concludes that polarization fields in the MQW and EBL are the physical origin of the efficiency droop, and that polarization-matched AlGaN can significantly enhance device efficiency at high current levels.The paper investigates the efficiency droop in GaInN/GaN multiple-quantum well (MQW) light-emitting diodes (LEDs). It finds that the efficiency droop, which occurs under high injection conditions, is not related to junction temperature but rather to carrier recombination outside the MQW region. Photoluminescence measurements show no droop when excitation power is varied, indicating that the droop is not due to MQW efficiency but to carrier escape from the MQW region. Simulations reveal that polarization fields in the MQW and electron blocking layer (EBL) enable electron escape, leading to the droop. The authors demonstrate that using quaternary AlGaN compositions can reduce these polarization effects, minimizing droop and improving efficiency. The study concludes that polarization fields in the MQW and EBL are the physical origin of the efficiency droop, and that polarization-matched AlGaN can significantly enhance device efficiency at high current levels.