Highly periodic, three-dimensionally arranged InGaAsN : Sb quantum dot arrays fabricated nonlithographically for optical devices

Abstract

A three-dimensional array of ∼55 nm diameter InGaAsN : Sb quantum dots (QDs) was nonlithographically fabricated starting with a MBE-grown InGaAsN : Sb/GaAs multiple quantum well wafer. The nonlithographic fabrication process relies on the use of a highly ordered nanopore alumina membrane for lateral patterning followed by a reactive ion etching. The dot size uniformity, spatial ordering and three-dimensional packing density are among the best reported so far. Nondestructive Raman scattering was employed to assess the material quality of the samples. While photoluminescence study points towards a moderately increased role of nonradiative transitions in the fabricated QD arrays, the dots show a relatively high emission intensity at room temperature, suggesting improved operation of long wavelength optical devices. Likely mechanisms contributing to the PL increase and the observed ∼50 meV red shift in the emission peak position are discussed. This study might be of great importance for engineering well controllable, ultra-high density, three-dimensionally arranged QD arrays for active optical devices.

Investigation of high‐T luminescence processes in ZnO nanorods grown catalytically by vapor‐transport method

“…To differentiate between the two other mechanisms, excitation-power dependent PL was acquired at different temperature ranges (low, medium and high T), whereas the results (not shown) consistently revealed a linear dependence of the emission intensity on the excitation intensity for all three temperature ranges. Based of the analysis reported before by some of us, in case of free electron-hole radiative recombination a linear relationship is expected only in combination with a strong radiative recombination, the latter is not the case here [9,10]. In fact, a strong decrease of the UV PL is taken as evidence of the increase in the role of non-radiative recombination processes with the onset of high T. At the same time, the dependence stays clearly linear which is a characteristic of excitonic emission and not of free electron-hole recombination or other recombinations such as those originating from free to bound transitions.…”

Light Emission by Nanoporous GaN Produced by a Top-Down, Nonlithographical Nanopatterning

“…While a drop in the reflection was reported to result in stronger PL signals, this was not the case for the np-GaN templates studied by us. The reduction of the emission intensity, observed experimentally, is in part attributed to a decline in the electric field and, in turn, absorption strength for mesoscopic structures that feature a high aspect ratio and large dielectric constant mismatch [22]. In the case of np-GaN, the polarizations, for which light absorption is to be weaker, are shown by arrows in Figure 1(a).…”

The use of Abel-Tersoff potentials in atomistic simulations of InGaAsSb/GaAs

“…the cases of defects inclusions [2], compositional disorder in complex ternary alloys and nanostructures [4,5]. Recently [6][7][8] much experimental work on quaternary alloys such as InGaAsN or InGaAsSb has generated a great deal of questions on the nature of the elastic properties of the binary compounds and how these are related to those of the quaternary alloys.…”