Effect of stoichiometric conditions and growth mode on threading dislocations filtering in AlN/c-Al2O3 templates grown by PA MBE

Нечаев, Д. В.; Koshelev, O. A.; Ратников, В. В.; Brunkov, P. N.; Myasoedov, A. V.; Ситникова, A. А.; Иванов, С. В.; Jmerik, V. N.

doi:10.1016/j.spmi.2019.106368

Cited by 23 publications

(29 citation statements)

References 27 publications

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“…Res. Ltd., Oxfordshire, UK) on standard c-Al 2 O 3 substrates using migrationenhanced epitaxy for the 65-nm-thick nucleation layer and multi-stage metal-modulated epitaxy (MME) for the rest buffer layer at a substrate temperature varied between 780-850 • C [34][35][36]. These templates have an RMS roughness of about 0.6 nm and threading dislocation densities of ~5 × 10 9 cm −2 .…”

Section: Methodsmentioning

confidence: 99%

Monolayer-Scale GaN/AlN Multiple Quantum Wells for High Power e-Beam Pumped UV-Emitters in the 240–270 nm Spectral Range

et al. 2021

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Monolayer (ML)-scale GaN/AlN multiple quantum well (MQW) structures for electron-beam-pumped ultraviolet (UV) emitters are grown on c-sapphire substrates by using plasma-assisted molecular beam epitaxy under controllable metal-rich conditions, which provides the spiral growth of densely packed atomically smooth hillocks without metal droplets. These structures have ML-stepped terrace-like surface topology in the entire QW thickness range from 0.75–7 ML and absence of stress at the well thickness below 2 ML. Satisfactory quantum confinement and mitigating the quantum-confined Stark effect in the stress-free MQW structures enable one to achieve the relatively bright UV cathodoluminescence with a narrow-line (~15 nm) in the sub-250-nm spectral range. The structures with many QWs (up to 400) exhibit the output optical power of ~1 W at 240 nm, when pumped by a standard thermionic-cathode (LaB6) electron gun at an electron energy of 20 keV and a current of 65 mA. This power is increased up to 11.8 W at an average excitation energy of 5 µJ per pulse, generated by the electron gun with a ferroelectric plasma cathode at an electron-beam energy of 12.5 keV and a current of 450 mA.

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Section: Methodsmentioning

confidence: 99%

Monolayer-Scale GaN/AlN Multiple Quantum Wells for High Power e-Beam Pumped UV-Emitters in the 240–270 nm Spectral Range

et al. 2021

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“…c–e) Reproduced with permission. [ 90 ] Copyright 2020, Elsevier. f) The product (stress × thickness) and incremental stress versus thickness dependences for AlN/c‐Al 2 O 3 template grown using various stoichiometric conditions.…”

Section: Comparative Analysis Of Mbe and Mocvd For Growing ML Gan/aln...mentioning

confidence: 99%

“…[ 16,62,89 ] Recently, we developed an alternative method (without GaN inserts) for reducing the total TD density to the level of 10 9 cm −2 due to optimization of migration‐enhanced epitaxy of AlN nucleation layers on c ‐ Al 2 O 3 substrates and elaboration of the two‐stage growth of AlN buffer layers, using metal‐modulated epitaxy (MME), to filter TDs and achieve finally the atomically smooth surface morphology with RMS roughness of 0.6 nm, as shown in Figure 3c,e. [ 90 ] Moreover, Figure 3f shows the discovered possibility to grow by this method thick‐enough AlN buffer layers controllably either without any stress or with only a small tensile stress (<0.2 GPa), which excludes cracking phenomena in these templates. [ 91 ]…”

Section: Comparative Analysis Of Mbe and Mocvd For Growing ML Gan/aln...mentioning

confidence: 99%

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Monolayer‐Thick GaN/AlN Multilayer Heterostructures for Deep‐Ultraviolet Optoelectronics

Jmerik

Торопов

Davydov

et al. 2021

Physica Rapid Research Ltrs

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Recent progress in the development of monolayer (ML)‐thick GaN/AlN multilayer heterostructures for deep‐ultraviolet (UV) optoelectronics is reviewed. Analysis of both plasma‐assisted molecular beam epitaxy and metal–organic vapor phase epitaxy shows that extreme interface sharpness and sub‐ML accuracy in setting the layer thickness are attractive features of the former, whereas the lowest density of threading dislocations and wide possibilities for the implementation of various 2D growth mechanisms are the advantages of the latter. The structural properties of ML GaN/AlN heterostructures are evaluated not only by standard X‐ray diffraction and scanning transmission electron microscopy, but also by Raman spectroscopy. Theoretical and experimental studies of the optical properties of ML‐thick GaN/AlN quantum wells (QWs) reveal that quenching of the quantum‐confined Stark effect, suppression of transverse electric transverse magnetic polarization switching, as well as the excitonic nature of UV‐radiative recombination in ultrathin (1–2 ML) QWs ensure in such structures a high internal quantum yield of 75% for UV radiation at 235 nm at room temperature. The possibilities of using ML‐GaN/AlN heterostructures to fabricate UVC emitters of spontaneous and stimulated emissions in a wide range of output powers with various pumping techniques are considered, and the most important problems are formulated.

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“…1(a), is grown by plasmaassisted molecular beam epitaxy (Compact21T, Riber) on a double-side polished c-sapphire wafer (c-Al2O3). Initially, a 1.6 µm thick AlN layer was grown using two-stage metalmodulated epitaxy to reduce the threading dislocation density to mid-10 9 cm -2 and to achieve an atomically smooth surface, as detailed in [16]. Then, 25 GaN QWs with a thickness of 1.8 nm, separated by 5nm thick AlN barriers layers, were formed using the sub-monolayer digital alloying method described in [17].…”

Section: Sample Overview and Optical Propertiesmentioning

confidence: 99%

Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays

Mundry

Spreyer

Jmerik

et al. 2021

Opt. Mater. Express

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We realize and investigate a nonlinear metasurface taking advantage of intersubband transitions in ultranarrow GaN/AlN multi-quantum well heterostructures. Owing to huge band offsets, the structures offer resonant transitions in the telecom window around 1.55 µm. These heterostructures are functionalized with an array of plasmonic antennas featuring crosspolarized resonances at these near-infrared wavelengths and their second harmonic. This kind of nonlinear metasurface allows for substantial second-harmonic generation at normal incidence which is completely absent for an antenna array without the multi-quantum well structure underneath. While the second harmonic is originally radiated only into the plane of the quantum wells, a proper geometrical arrangement of the plasmonic elements permits to redirect the second-harmonic light to free-space radiation, which is emitted perpendicular to the surface.

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Effect of stoichiometric conditions and growth mode on threading dislocations filtering in AlN/c-Al2O3 templates grown by PA MBE

Cited by 23 publications

References 27 publications

Monolayer-Scale GaN/AlN Multiple Quantum Wells for High Power e-Beam Pumped UV-Emitters in the 240–270 nm Spectral Range

Monolayer-Scale GaN/AlN Multiple Quantum Wells for High Power e-Beam Pumped UV-Emitters in the 240–270 nm Spectral Range

Monolayer‐Thick GaN/AlN Multilayer Heterostructures for Deep‐Ultraviolet Optoelectronics

Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays

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