Growth-Temperature Dependence of Wetting Layer Formation in High Density InGaAs/GaAs Quantum Dot Structures Grown by Droplet Epitaxy

Zuerbig, Verena; Bugaew, Natalia; Reithmaier, Johann Peter; Kozub, Michał; Musiał, Anna; Sęk, G.; Misiewicz, J.

doi:10.1143/jjap.51.085501

Cited by 6 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Individual QDs; QDs diads [2,36,37]; single and multiple quantum rings (QRs) [16,21,[38][39][40][41][42][43]; hybrid QD-QR structures, such as ring-on-adisk [44], dot in-a-ring [45], or dot-on-a-disk [46]; and quantum wires [47] are remarkable examples of the possibilities offered by this self-assembly technique. In addition to this, DE allows forming QDs without a wetting layer [47][48][49][50][51][52][53][54][55], and their size and density can be independently tuned [56]. These features are not easily obtained with other methods such as conventional Stranski-Krastanov growth based on accumulation and relaxation of strain [57].…”

Section: Introductionmentioning

confidence: 99%

Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy

et al. 2021

View full text Add to dashboard Cite

We provide an extensive and systematic investigation of exciton dynamics in droplet epitaxial quantum dots comparing the cases of (311)A, (001), and (111)A surfaces. Despite a similar s-shell exciton structure common to the three cases, the absence of a wetting layer for (311)A and (111)A samples leads to a larger carrier confinement compared to (001), where a wetting layer is present. This leads to a more pronounced dependence of the binding energies of s-shell excitons on the quantum dot size and to the strong anti-binding character of the positive-charged exciton for smaller quantum dots. In-plane geometrical anisotropies of (311)A and (001) quantum dots lead to a large electron-hole fine interaction (fine structure splitting (FSS) ∼100 μeV), whereas for the three-fold symmetric (111)A counterpart, this figure of merit is reduced by about one order of magnitude. In all these cases, we do not observe any size dependence of the fine structure splitting. Heavy-hole/light-hole mixing is present in all the studied cases, leading to a broad spread of linear polarization anisotropy (from 0 up to about 50%) irrespective of surface orientation (symmetry of the confinement), fine structure splitting, and nanostructure size. These results are important for the further development of ideal single and entangled photon sources based on semiconductor quantum dots.

show abstract

Section: Introductionmentioning

confidence: 99%

Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Within this class of QDs, droplet epitaxy (DE) [ 10 , 13 , 14 ] and droplet etching [ 9 , 15 , 16 ] (alternative growth protocols to Stranski–Krastanov for strain-free III–V-based semiconductor nanostructures), enabled the fabrication of state-of-the-art devices such as lasers [ 17 , 18 , 19 , 20 , 21 ] and quantum emitters, including single-photon sources [ 22 , 23 , 24 , 25 , 26 ] and entangled photons [ 9 , 27 , 28 , 29 , 30 ] with electrical injection [ 31 ]. The versatility of this method allowed to grow many different semiconductor alloys (GaInSb [ 32 ], AlGaAs [ 33 , 34 , 35 , 36 , 37 ], InGaAs [ 38 , 39 , 40 , 41 , 42 , 43 , 44 ], and InGaP [ 26 , 45 , 46 ]), forming a plethora of nanostructures [ 47 ] such as quantum dots (QDs); QDs diads [ 48 , 49 , 50 ]; multiple-concentric quantum rings [ 18 , 23 , 51 , 52 ...…”

Section: Introductionmentioning

confidence: 99%

“…The versatility of this method allowed to grow many different semiconductor alloys (GaInSb [ 32 ], AlGaAs [ 33 , 34 , 35 , 36 , 37 ], InGaAs [ 38 , 39 , 40 , 41 , 42 , 43 , 44 ], and InGaP [ 26 , 45 , 46 ]), forming a plethora of nanostructures [ 47 ] such as quantum dots (QDs); QDs diads [ 48 , 49 , 50 ]; multiple-concentric quantum rings [ 18 , 23 , 51 , 52 , 53 , 54 , 55 , 56 ]; coupled structures such as ring-on-a-disk [ 57 ], dot in-a-ring [ 58 ], or dot-on-a-disk [ 59 ]; as well as elongated structures such as nanowires [ 60 ]. This technique allows to independently tune the size and density of the nanostructures [ 61 ] and to grow them with or without a wetting layer [ 35 , 39 , 40 , 60 , 62 , 63 , 64 , 65 , 66 ], aspects that are not matched by the conventional Stranski–Krastanov approach based on strain [ 67 ].…”

Section: Introductionmentioning

confidence: 99%

Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A-Oriented Substrates

et al. 2020

View full text Add to dashboard Cite

Droplet epitaxy allows the efficient fabrication of a plethora of 3D, III–V-based nanostructures on different crystalline orientations. Quantum dots grown on a (311)A-oriented surface are obtained with record surface density, with or without a wetting layer. These are appealing features for quantum dot lasing, thanks to the large density of quantum emitters and a truly 3D lateral confinement. However, the intimate photophysics of this class of nanostructures has not yet been investigated. Here, we address the main optical and electronic properties of s-shell excitons in individual quantum dots grown on (311)A substrates with photoluminescence spectroscopy experiments. We show the presence of neutral exciton and biexciton as well as positive and negative charged excitons. We investigate the origins of spectral broadening, identifying them in spectral diffusion at low temperature and phonon interaction at higher temperature, the presence of fine interactions between electron and hole spin, and a relevant heavy-hole/light-hole mixing. We interpret the level filling with a simple Poissonian model reproducing the power excitation dependence of the s-shell excitons. These results are relevant for the further improvement of this class of quantum emitters and their exploitation as single-photon sources for low-density samples as well as for efficient lasers for high-density samples.

show abstract

“…The continuous development of droplet epitaxy (DE) [1][2][3] as growth protocol for III-V-based semiconductor nanostructures enabled the fabrication of state-of-the-art devices such as lasers [4][5][6][7][8] and quantum emitters, including single photon sources [9][10][11][12][13] and entangled photons [14][15][16][17] with electrical injection [18]. The versatility of this method allowed to grow many different semiconductor alloys (GaInSb[19], AlGaAs [20][21][22][23][24], InGaAs [25][26][27][28][29][30][31] InGaP [13,32,33]), forming a plethora of nanostructures [34] such as quantum dots (QDs), multiple-concentric quantum rings [5,10,[35][36][37][38][39][40], coupled structures such as ring-on-a-disk [41], dot in-a-ring [42] or dot-on-a-disk [43], as well as elongated structur...…”

Section: Introductionmentioning

confidence: 99%

Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A Oriented Substrates

Abbarchi¹,

Mano²,

Kuroda³

et al. 2020

Preprint

View full text Add to dashboard Cite

Droplet epitaxy allows the efficient fabrication of a plethora of 3D, III-V-based nanostructures on different crystalline orientations. Quantum dots grown on (311)A-oriented surface are obtained with record surface density, with or without a wetting layer. These are appealing features for quantum-dot lasing, thanks to the large density of quantum emitters and a truly 3D lateral confinement. However, the intimate photophysics of this class of nanostructures has not yet been investigated. Here we address the main optical and electronic properties of s-shell excitons in individual quantum dots grown on (311)A substrates with photoluminescence spectroscopy experiments. We show the presence of neutral exciton and biexciton as well as positive and negative charged excitons. We investigate the origins of spectral broadening, identifying them in spectral diffusion at low temperature and phonon-interaction at higher temperature, the presence of fine interactions between electron and hole spin, and a relevant heavy-hole/light-hole mixing. We interpret the level filling with a simple Poissonian model reproducing the power excitation dependence of the s-shell excitons. These results are relevant for the further improvement of this class of quantum emitters and their exploitation as single photon sources for low density samples as well as for efficient lasers for high density samples.

show abstract

Growth-Temperature Dependence of Wetting Layer Formation in High Density InGaAs/GaAs Quantum Dot Structures Grown by Droplet Epitaxy

Cited by 6 publications

References 17 publications

Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy

Polarization Anisotropies in Strain-Free, Asymmetric, and Symmetric Quantum Dots Grown by Droplet Epitaxy

Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A-Oriented Substrates

Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A Oriented Substrates

Contact Info

Product

Resources

About