Effect of barrier thickness on photoelectric properties of InGaN/GaN asymmetric multiple-quantum-well structure light-emitting diode

Abstract

GaN/GaInN asymmetric multiple quantum well light-emitting diodes with varying potential barrier thicknesses (5 and 15 nm) are grown by using metal organic chemical vapor deposition. The narrow barrier structure improves the performance of the device, including the super-linear increase of electroluminescence integral intensity, the mitigation of efficiency droop at high current density, the reduction of wavelength drift, the reduction of forward voltage, and the improvement of wall-plug efficiency. This is due to the narrowing of the thickness of the quantum barrier, which results in the smaller electric field among the quantum well, the weakening of the quantum confinement Stark effect, the more uniform distribution of carriers across the active region of the device, and the suppression of electron leakage.

Optimizing performance and energy consumption in GaN(n)/In x Ga 1- x N/GaN/AlGaN/GaN(p) light emitting diodes by quantum-well number and mole fraction

“…These electric field values are consistent with Bernardini et al [59] and Chow et al [60,61]. It is also noted that the electric field is almost constant in the InxGa1-xN well, which leads to a linear form offset of conduction and valence bands in the wells [62]. In the GaN barrier, the linear electric field form leads to a parabolic offset form of conduction and valence bands [55], Figure 4.…”

Design and analysis of a group-III nitride superlattice structure based semiconductor laser diode for blue region emission

“…As a result, the introduced holes typically concentrate in the quantum wells (QWs) closest to the p-GaN side, resulting in a smaller density of holes in other QWs and considerable electron losses, resulting in a reduction in overall efficiency. The asymmetric InGaN QW design has been found to be one of the most successful methods for improving carrier concentration in the active zone and minimizing electron loss from the wells [9].…”

“…In the many QW regions with thin barriers, where hole transport and tunneling are better, more evenly distributed holes and a lower density of carriers can be obtained at a higher injected current density. Then, for all QWs, the hole can efficiently recombine with electrons, decreasing the excessive concentration of holes found in the first QW towards the p-type side and help in better radiative recombination [9].…”

Resonant Tunneling of Electrons and Holes through the InxGa1−xN/GaN Parabolic Quantum Well/LED Structure

“…Likewise, for stepped In 0.2 GaN 0.8 /GaN quantum well-LED structures, the researchers experimentally determined that the thin barrier structure enhanced the device's performance and decreased efficiency droop at high current density. This may be caused by poor hole tunneling through the thick barrier, causing electron leakage from the active region [8], while a theoretical study for parabolic In 0.2 GaN 0.8 /GaN quantum well-LED structures found that a thick barrier structure significantly increased efficiency [4].…”