Effect of Cap Thickness on InAs/InP Quantum Dots Grown by Droplet Epitaxy in Metal–Organic Vapor Phase Epitaxy

Abstract

InAs quantum dots (QDs) are grown on bare InP(001) via droplet epitaxy (DE) in metal-organic vapor phase epitaxy (MOVPE). Capping layer engineering, used to control QD size and shape, is explored for DE QDs in MOVPE. The method allows for the tuning of the QD emission over a broad range of wavelengths, ranging from the O-to the L-band. The effect of varying the InP capping layer is investigated optically by macro-and micro-photoluminescence (PL, μPL) and morphologically by transmission electron microscopy (TEM). A strong 500 nm blueshift of the QD emission wavelength is observed when the capping layer is reduced from 20 to 8 nm, which is reflected by a clear size reduction of the buried QDs.

Control of Morphology and Substrate Etching in InAs/InP Droplet Epitaxy Quantum Dots for Single and Entangled Photon Emitters

“…An indium flow of 20 sccm was supplied for 35 s for indium droplet deposition in all the layers, and an arsenic flow of 0.5 sccm was maintained during the whole crystallization process. Detailed growth sequence, atomic force microscopy (AFM), and photoluminescence (PL) measurements on identical QDs were reported by Sala et al ,, …”

“…An indium flow of 20 sccm was supplied for 35 s for indium droplet deposition in all the layers, and an arsenic flow of 0.5 sccm was maintained during the whole crystallization process. Detailed growth sequence, atomic force microscopy (AFM), and photoluminescence (PL) measurements on identical QDs were reported by Sala et al 22,35,57 The X-STM measurements were performed in a conventional Omicron low-temperature STM at 77 K under ultrahigh vacuum (UHV) with a base pressure of (4−6) × 10 −11 mbar. The sample was cleaved in UHV to reveal one of the {110} natural cleaving planes of zincblende crystal.…”

Dimension-Dependent Phenomenological Model of Excitonic Electric Dipole in InGaAs Quantum Dots

“…The model relies only on the validation of the approximation from Equation (1), derived under assumptions: (i) the QD has type-I confinement, (ii) it consists from piezoelectric material with dominant second-order term B 124 , and (iii) the hydrostatic strain around QD is mostly driven by the material mismatch between the dot and the substrate η QD H . Because the model is proportional not only to QD geometry but also to material parameters, it can be, therefore, expected to be applicable also for other III-V QD systems [14,[34][35][36][37] with type-I confinement where the electric dipole is aligned only along the dot growth direction.…”

Self‐Assembled InAs Quantum Dots on InGaAsP/InP(100) by Modified Droplet Epitaxy in Metal–Organic Vapor Phase Epitaxy around the Telecom C‐Band for Quantum Photonic Applications

“…[10,11] Droplet epitaxy (DE) in metal-organic vapor phase epitaxy (MOVPE) is a recent and very promising approach for QD fabrication, as it combines a large-scale epitaxial technique and a versatile epitaxial method. [12][13][14][15] This is a relatively new process that is not fully understood in terms of growth dynamics, particularly for III-V material systems compatible with telecom wavelengths, such as InAs/InP. Thus, it holds great potential for further development in the fabrication of telecom QDs for a broad range of applications.…”

“…Compared to the standard SK mode for QD growth, DE is a much more versatile method allowing for the fabrication of QDs and nanostructures with a wider range of material combinations as it does not rely on lattice-mismatch for nanostructure formation, but on crystallization of group III metallic droplets. [21] Previously, we studied InAs DE QDs on both bare InP [12,13] and on an In 0.53 Ga 0.47 As surface lattice matched to InP. [14] The latter showed QD nucleation following a modified DE mode compared to growth on InP, without the formation of etch pits around the QDs and generally higher QD density of 10 8 -10 10 cm À2 were achieved.…”