Enhanced radiative recombination and suppressed Auger process in semipolar and nonpolar InGaN/GaN quantum wells grown over GaN nanowires

Abstract

The mechanism behind the improved light emission properties of semipolar and nonpolar InGaN/GaN multiple quantum wells (MQWs) conformally grown over n-GaN nanowires (NWs) was studied using variable-temperature photoluminescence and time-resolved photoluminescence (TRPL). A reduced internal polarization electric field was found to account for the observed enhancement in the radiative recombination rate and internal quantum efficiency of the MQWs on NWs. Additionally, the excitation-dependent TRPL results indicate a significantly depressed Auger recombination in MQWs grown on NWs that can be attributed to the feature of ultralow dislocation density of the MQWs grown over GaN nanostructures.

Structural and optical impacts of AlGaN undershells on coaxial GaInN/GaN multiple-quantum-shells nanowires

“…The fitted carrier lifetimes (fast component) for samples b and d are 2.19 ns and 8.44 ns, respectively. It was reported that point defects and impurities are the main factors determining emission intensity rather than threading dislocations [22,23,40]. Hence, it reveals that the emission intensity in MQS increases by employing the AlGaN undershell, mainly due to the reduction of point defects density in the MQS active area including the c-, r-, and m-planes.…”

“…However, the dislocation defects and triangular defects determine the weaker emissions than that of m-planes. The internal quantum efficiency (IQE) value can be approximately derived by comparing PL intensity at room temperature with respect to that measured at low temperature [40]: IQE(RT) = I(RT)/ I(LT), where I(RT) and I(LT) denote the integrated intensity of PL measured at room temperature (300 K) and low temperature (12 K). Assuming the IQE at 12 K is 100%, the estimated IQE values for samples b and d are 29.32% and 35.52% at room temperature, respectively.…”

Internal quantum efficiency improvement of InGaN/GaN multiple quantum well green light-emitting diodes

“…Relieved QCSE was hence achieved with an improved overlap of electron−hole wave functions for MQW. Conse− quently, the probability of dipole transition in the semipolar and nonpolar QWs was enhanced for more efficient radia− tive recombination [44]. Strain is directly responsible for the piezoelectric polar− ization.…”

Using InGaN/GaN Multiple Quantum well Green light-Emitting Diodes as a Promising Replacement of Conventional light Sources

“…Within the SBMQWs, thicknesses & compositions are selected with the aim which the compressive worry within the wells is modified through the flexible stress within the obstacles. R. Arvind Pawan et al planned a novel highlow indium make up and then prestrained the InGaN/GaN MQW system of environmentally friendly LED [33]. With this MQW the original 4 QWs possess a reduced indium aspect contained InxGa1?…”