High spatial uniformity of photoluminescence spectra in semipolar (202¯1) plane InGaN/GaN quantum wells

Abstract

Articles you may be interested inTemporally and spatially resolved photoluminescence investigation of ( 11 2 ¯ 2 ) semi-polar InGaN/GaN multiple quantum wells grown on nanorod templates Appl. Phys. Lett. 105, 261103 (2014); 10.1063/1.4905191Highly polarized photoluminescence and its dynamics in semipolar ( 20 2 ¯ 1 ¯ ) InGaN/GaN quantum well Appl. Phys. Lett.High optical polarization ratio of semipolar ( 20 2 ¯ 1 ¯ ) -oriented InGaN/GaN quantum wells and comparison with experiment J. Appl. Phys. 112, 093106 (2012); 10.1063/1.4764316 Dynamics of polarized photoluminescence in m -plane InGaN/GaN quantum wellsScanning near-field optical spectroscopy was applied to study spatial variations of emission spectra at room temperature in semipolar ð20 21Þ In x Ga 1Àx N/GaN single quantum wells (QWs) for 0:11 x 0:36. Photoluminescence (PL) was found to be highly uniform, with peak wavelength deviations and peak intensity deviations divided by average values in the range of 6-12 meV and 0.03-0.07, respectively. Near-field maps of PL parameters showed large, $5 to 10 lm size areas of similar values, as opposed to 100 nm scale variations, often reported for InGaN QWs. The nearfield PL spectra were found to broaden with increasing InN molar fraction. In the low In content QWs, the broadening is primarily determined by the random cation distribution, while for larger InN molar fractions 10 nm scale localization sites with increasingly deeper band potentials are suggested as the linewidth broadening cause. V C 2015 AIP Publishing LLC.

Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

“…Also, the poor thermal conductivity of the p-DBR layers prevents efficient heat dissipation, which may exacerbate filamentation. Considering the length scale of experimentally measured indium fluctuations, [71][72][73] it is unlikely that this is the cause of the non-uniformity in 405 nm VCSELs, though it may play a strong role at longer wavelengths. Next, given that the epitaxial growth and ITO employed in this device have <1 nm RMS roughness, it is unlikely that rough surface morphology on the p-side of the device is resulting in the non-uniformity.…”

Enabling area-selective potential-energy engineering in InGaN/GaN quantum wells by post-growth intermixing

“…As expected, the FWHM (full width at half maximum) of PL peak in the non-intermixed region was found to increase from 0.160 eV (in as-grown sample) to 0.175 eV. The broad PL FWHM is mainly due to potential fluctuations related to inhomogeneous broadening arising from spatial variation in the indium composition, which can be better resolved using near-field PL measurements [24]. In our case, far-field PL measurement inadvertently collected PL signals from a larger area, and therefore the larger spatial indium compositional variation was measured.…”

Energy Transfer between Cyano‐Ether PPV and InGaN/GaN Quantum Wells with Large Piezoelectric Fields

“…TEM investigations revealed no unusual fluctuation of the indium content or the well width. The contribution of localization to the Stokes shift is on the order of 0.1 eV . Therefore, the low PL emission energy of the present QW has to be caused by an even higher internal electric field than assumed in the above calculations.…”