Promotion of electron confinement and hole injection in GaN-based green light-emitting diodes with a hybrid electron blocking layer

摘要

The InGaN/GaN green light-emitting diode (LED) with a hybrid electron blocking layer (HEBL) formed by partially incorporating a small amount of indium in the AlGaN conventional electron blocking layer is proposed. Influence of the HEBL is investigated both experimentally and theoretically. By fitting the quantum efficiency with the modified ABCD model, these coefficients' values are obtained and the reduced value of D suggests that the HEBL can weaken the carrier leakage. Subsequent simulation shows that the proposed design builds up two higher potential barriers for electrons and one lower potential barrier for holes, which could effectively enhance electron confinement and hole injection. Therefore more carriers could be restricted in multiple quantum wells and participate in radiative recombination. As a result, the measured light output power of the proposed LED is 80% higher than that of the reference LED at a current of 150 mA and its external quantum efficiency droop ratio is also smaller.