Light emission by point dipole located inside spherical (semiconductor) particle in the vicinity of a spherical metal particle

• Veröffentlicht in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Datum: 2013
• Hauptverfasser: Kryuchenko, Yu.V., Korbutyak, D.V.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2013
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/117730
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Light emission by point dipole located inside spherical
 (semiconductor) particle in the vicinity of a spherical metal particle /Yu.V. Kryuchenko and D.V. Korbutyak // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2013. — Т. 16, № 3. — С. 227-239. — Бібліогр.: 17 назв. — англ.

Proposed in this work is a theoretical model that enables to correctly calculate
 light emission characteristics of a hybrid nanosystem formed by a spherical
 semiconductor quantum dot (QD) and spherical metal nanoparticle (NP) when QD is
 excited by light. The QD that emits mainly dipole-type electromagnetic (EM) field can
 not be considered as a point dipole at small separation distances between QD and NP (of
 the same order as the QD size). However, only the “point dipole” concept of QD is used
 in all currently known theoretical models of hybrid nanosystems. Correspondingly,
 unlike a simulated “point dipole + spherical metal NP”, the real hybrid nanosystem is
 nonspherical as a whole. In this work: i) relations have been obtained between the
 coefficients of EM field multipole expansions in two spherical coordinate systems with
 their origins in semiconductor QD and metal NP. As a result, spherical symmetry of
 semiconductor QD and metal NP can be used separately to solve the equations related to
 boundary conditions at their surfaces; ii) it has been shown that EM field emitted by QD
 can be represented as a sum of contributions of all crystal unit cells forming QD and that
 each unit cell can be considered as an emitting point dipole. The contribution of a
 particular unit cell to the total EM field is determined by the exciton wave function;
 iii) to be closer to the real situation, the contribution εib(ω) of interband transitions to
 the NP permittivity has been taken into account in the visible spectral range.