Performance improvement of InGaN/GaN light-emitting diodes using parabolic quantum well

The effect of optical performance for light-emitting diodes (LEDs) using InGaN/GaN parabolic quantum well (PQW) has been studied in terms of transition probability (TP) and internal quantum efficiency. The performance analyses on the light of energy band structure, carrier concentration profile, electric field distribution and radiative recombination rate. Introduction of parabolic QW (PQW) decreases the build-in polarization field effect and increases carrier injection in the well, hence radiative recombination rate is increased. Also, the PQW increases the overlapping between electron and hole wave functions, thus the TP is enhanced. Our proposed PQW LED exhibits 3 times higher TP and lower the efficiency droop, only 39% in contrast to 58.6% for conventional InGaN/GaN rectangular QW LED.