2 research outputs found
Optical and electronic properties of low-density InAs/InP quantum dot-like structures devoted to single-photon emitters at telecom wavelengths
Due to their band-structure and optical properties, InAs/InP quantum dots
(QDs) constitute a promising system for single-photon generation at third
telecom window of silica fibers and for applications in quantum communication
networks. However, obtaining the necessary low in-plane density of emitters
remains a challenge. Such structures are also still less explored than their
InAs/GaAs counterparts regarding optical properties of confined carriers. Here,
we report on the growth via metal-organic vapor phase epitaxy and investigation
of low-density InAs/InP QD-like structures, emitting in the range of 1.2-1.7
m, which includes the S, C, and L bands of the third optical window. We
observe multiple photoluminescence (PL) peaks originating from flat QDs with
height of small integer numbers of material monolayers. Temperature-dependent
PL reveals redistribution of carriers between families of QDs. Via
time-resolved PL, we obtain radiative lifetimes nearly independent of emission
energy in contrast to previous reports on InAs/InP QDs, which we attribute to
strongly height-dependent electron-hole correlations. Additionally, we observe
neutral and charged exciton emission from spatially isolated emitters. Using
the 8-band kp model and configuration-interaction method, we
successfully reproduce energies of emission lines, the dispersion of exciton
lifetimes, carrier activation energies, as well as the biexciton binding
energy, which allows for a detailed and comprehensive analysis of the
underlying physics.Comment: 13 pages, 9 figure