4 research outputs found
Photoluminescence of tetrahedral quantum-dot quantum wells
Taking into account the tetrahedral shape of a quantum dot quantum well
(QDQW) when describing excitonic states, phonon modes and the exciton-phonon
interaction in the structure, we obtain within a non-adiabatic approach a
quantitative interpretation of the photoluminescence spectrum of a single
CdS/HgS/CdS QDQW. We find that the exciton ground state in a tetrahedral QDQW
is bright, in contrast to the dark ground state for a spherical QDQW. The
position of the phonon peaks in the photoluminescence spectrum is attributed to
interface optical phonons. We also show that the experimental value of the
Huang-Rhys parameter can be obtained only within the nonadiabatic theory of
phonon-assisted transitions.Comment: 4 pages, 4 figures, E-mail addresses: [email protected],
[email protected], [email protected], [email protected],
to be published in Phys. Rev. Letter
Resonant terahertz light absorption by virtue of tunable hybrid interface phonon-plasmon modes in semiconductor nanoshells
Resonant Terahertz Light Absorption by Virtue of Tunable Hybrid Interface Phonon–Plasmon Modes in Semiconductor Nanoshells
Metallic nanoshells have proven to be particularly versatile, with applications in biomedical imaging and surface-enhanced Raman spectroscopy. Here, we theoretically demonstrate that hybrid phonon-plasmon modes in semiconductor nanoshells offer similar advantages in the terahertz regime. We show that, depending on tm,n,nhe doping of the semiconductor shells, terahertz light absorption in these nanostructures can be resonantly enhanced due to the strong coupling between interface plasmons and phonons. A threefold to fourfold increase in the absorption peak intensity was achieved at specific values of electron concentration. Doping, as well as adapting the nanoshell radius, allowed for fine-tuning of the absorption peak frequencies