Micro‐photoluminescence studies of InGaN/GaN quantum dots up to 150 K

Sebald, K.; Lohmeyer, H.; Gutowski, J.; Yamaguchi, Tomohiro; Hommel, D.

doi:10.1002/pssb.200565407

Cited by 28 publications

(33 citation statements)

References 14 publications

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“…These problems were overcome by development of a new growth technique for InGaN quantum dot formation [44], where an InGaN nucleation layer of 1-2 nm thickness and nominal concentration of 0.4 is stabilised by an InGaN formation layer of about 7 nm thickness and nominal concentration of 0.1. The capped structure exhibits quantum dot luminescence [45], and TEM analysis revealed that the quantum dot emission most probably stems from indium rich regions with diameters of $5 nm [46]. This growth approach is suitable for incorporation of InGaN quantum dots between two DBRs.…”

Section: Discussionmentioning

confidence: 98%

Microstructural and compositional analyses of GaN‐based nanostructures

Pretorius

Schmidt

Aschenbrenner

et al. 2011

Physica Status Solidi (b)

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Composition and microstructure of GaN-based island structures and distributed Bragg reflectors (DBRs) were investigated with transmission electron microscopy (TEM). We analysed free-standing InGaN islands and islands capped with GaN. Growth of the islands performed by molecular beam epitaxy (MBE) and metal organic vapour phase epitaxy (MOVPE) resulted in different microstructures. The islands grown by MBE were plastically relaxed. Cap layer deposition resulted in a rapid dissolution of the islands already at early stages of cap layer growth. These findings are confirmed by grazingincidence X-ray diffraction (GIXRD). In contrast, the islands grown by MOVPE relax only elastically.Strain state analysis (SSA) revealed that the indium concentration increases towards the tips of the islands. For an application as quantum dots, the islands must be embedded into DBRs. Structure and composition of Al y Ga 1-y N/GaN Bragg reflectors on top of an AlGaN buffer layer and In x Al 1-x N/ GaN Bragg reflectors on top of a GaN buffer layer were investigated. Specifically, structural defects such as threading dislocations (TDs) and inversion domains (IDs) were studied, and we investigated thicknesses, interfaces and interface roughnesses of the layers. As the peak reflectivities of the investigated DBRs do not reach the theoretical predictions, possible reasons are discussed.

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Section: Discussionmentioning

confidence: 98%

Microstructural and compositional analyses of GaN‐based nanostructures

Pretorius

Schmidt

Aschenbrenner

et al. 2011

Physica Status Solidi (b)

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“…The acoustic phonon scattering strength, activation energy of higher order broadening process, and linewidth values measured at elevated temperatures are all in good agreement with reports in the nitride literature. 22,42 Isolation of the QD emission allowed us to assess more accurately its characteristics. We used a pair of bandpass filters to select the wavelength range of interest, before carrying out further optical characterisation.…”

Section: Resultsmentioning

confidence: 99%

Polarisation-controlled single photon emission at high temperatures from InGaN quantum dots

et al. 2017

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a Solid-state single photon sources with polarisation control operating beyond the Peltier cooling barrier of 200 K are desirable for a variety of applications in quantum technology. Using a non-polar InGaN system, we report the successful realisation of single photon emission with a g (2) (0) of 0.21, a high polarisation degree of 0.80, a fixed polarisation axis determined by the underlying crystallography, and a GHz repetition rate with a radiative lifetime of 357 ps at 220 K in semiconductor quantum dots. The temperature insensitivity of these properties, together with the simple planar epitaxial growth method and absence of complex device geometries, demonstrates that fast single photon emission with polarisation control can be achieved in solid-state quantum dots above the Peltier temperature threshold, making this system a potential candidate for future on-chip applications in integrated systems.

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“…Negative binding energies have been reported previously for biexcitons in In x Ga 1-x N QDs. 20,21 From the x-and y-polarized spectra of peaks X and XX, no FSS could be resolved for this or other QDs measured in this geometry.…”

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confidence: 93%