Performance enhancement of InGaN-based light-emitting diodes with InGaN/AlInN/InGaN composition-graded barriers

Abstract

A new structure with InGaN/AlInN/InGaN composition-graded barriers for a nitride-based light-emitting diode (LED) has been proposed and analyzed numerically. The energy band diagrams, the electrostatic fields, the carrier concentrations in the quantum well, the light output power and the internal quantum efficiency are investigated. Numerical simulation results suggest that the new structure contributes to a more uniform carrier concentration distribution, a smaller polarization electrostatic field and a more effective confinement of electrons in the active region. As a result, LEDs with this new structure attain a higher optical output power and a reduced efficiency droop of 24.7% compared with 66.6% in a conventional LED.

Device Simulation on GaN‐LED Operating in Noncarrier Injection Mode for Performance Improvement by Enhancing the Tunneling Effect in Multiquantum Wells

“…Thus, the electron concentration in the n-GaN terminal decreases to form a depletion region, and an induced electric field from n-GaN to p-GaN is generated, which is different from the conventional LED. [37][38][39] The consumption of electrons in the n-GaN terminal is the largest at the peak voltage. The minimum electron concentration at the terminal boundary is about 2 × 10 12 cm −3 .…”

Performance enhancement of InGaN LEDs with Al-graded GaN/AlGaN multiple electron-blocking layers

“…Consequently, several different energy-band engineering designs for EBLs have been suggested, including InGaN= AlInN=InGaN superlattice (SL) EBLs, triangular p-AlGaN= GaN=AlGaN EBLs, and AlGaN=GaN SLs. [14][15][16][17][18] The purposes of these designs were to improve the injection hole concentration and enhance the radiative recombination rate in MQWs. However, achieving such an ideal EBL is difficult because of the high ionization energy of the p-type dopant Mg in the AlGaN layer and the self-compensation effect in highly doped GaN-based materials.…”