Epitaxial growth of crystal phase quantum dots in III–V semiconductor nanowires

Abstract

Crystal phase quantum dots (QDs) are formed during the axial growth of III-V semiconductor nanowires (NWs) by stacking different crystal phases of the same material. In III-V semiconductor NWs, both...

Zincblende InAsxP1–x/InP Quantum Dot Nanowires for Telecom Wavelength Emission

“…26 In the last 2 decades, the realization of SPSs emitting at the telecom band has also been demonstrated in semiconductor QDs epitaxially grown in nanowires (NWs). 27,28 The exploitation of NW QDs has some important advantages compared to other types of QDs (such as Stranski− Krastanov QDs): (i) the growth mechanism of heterostructured NWs forming the QD leads to the possibility to control and tune QD features like QD dimensions, crystal phase, 29 composition, and density; (ii) semiconductor NWs open up the possibility to also grow highly lattice-mismatched heterostructures as a result of the relaxation of the elastic strain in the radial direction; 30 (iii) vapor−liquid−solid (VLS) growth of the NWs makes it possible to control the position in which the QDs are grown, both on the substrate and along the axis of the NW, opening up the possibility to grow coupled QDs in the same NW, which are naturally aligned along the NW axis; 31,32 waveguide directly around the QD, realizing what has been commonly called a "nanowire antenna" and increasing the extraction efficiency of the emitter. 33 Among the possible heterostructures explored in the literature for telecom emission, InAs x P 1−x QDs in InP NWs have been investigated.…”

“…In particular, SPSs at telecom bands are interesting for ultrasecure quantum optical communication using existing fiber networks, because at these wavelengths there is a minimum for the losses and the dispersion in telecommunication fibers. , Indeed, semiconductor QDs have been proven as efficient sources in the telecom band, − emitting on-demand high-purity single and indistinguishable photons or even polarization-entangled photon pairs. − Many crucial milestones concerning application of QD-based devices in secure quantum information technology have been reported, including sources with high efficiency of single-photon emission, − operation at elevated temperatures, ,, integration with a silicon platform, deterministic fabrication of QD structures, and fully integrated, fiber-coupled QD-based sources of single photons, including demonstration of quantum communication schemes . In the last 2 decades, the realization of SPSs emitting at the telecom band has also been demonstrated in semiconductor QDs epitaxially grown in nanowires (NWs). , The exploitation of NW QDs has some important advantages compared to other types of QDs (such as Stranski–Krastanov QDs): (i) the growth mechanism of heterostructured NWs forming the QD leads to the possibility to control and tune QD features like QD dimensions, crystal phase, composition, and density; (ii) semiconductor NWs open up the possibility to also grow highly lattice-mismatched heterostructures as a result of the relaxation of the elastic strain in the radial direction; (iii) vapor–liquid–solid (VLS) growth of the NWs makes it possible to control the position in which the QDs are grown, both on the substrate and along the axis of the NW, opening up the possibility to grow coupled QDs in the same NW, which are naturally aligned along the NW axis; , and (iv) it is possible to epitaxially grow a waveguide directly around the QD, realizing what has been commonly called a “nanowire antenna” and increasing the extraction efficiency of the emitter …”