Modeling the PbS quantum dots complex dielectric function by adjusting the E-k diagram critical points of bulk PbS

Elad Hechster, Gabby Sarusi

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

The complex dielectric function ϵ(E)=ϵR(E)+iϵI(E) of a semiconductor is a key parameter that dictates the material's optical and electrical properties. Surprisingly, the ϵ(E) of Lead Sulfide (PbS) quantum dots (QDs) has not been widely studied. In the present work, we develop a new model that aims to simulate the ϵ(E) of QDs. Our model is based on the fact that the quantum confinement in the nano regime affects all the electronic transitions throughout the entire Brillouin zone. Hence, as a first approximation, we attribute an equal contribution of energy, equivalent to the bandgap broadening, to each critical point (CP) in the E-k diagram. This is mathematically realized by adding these energy contributions to the central energy parameters of the Lorentz oscillator model. In order to validate our model, we used the CP parameters of bulk PbS to simulate the ϵ(E) of PbS QDs. Next, we use Maxwell Relations to calculate the refractive index and the extinction coefficient of PbS QDs from ϵE. Our results were compared with those published in the previous literature and showed good agreement. Our findings open a new avenue that may enable the calculation of the ϵE for nanoparticle systems.

Original languageEnglish
Article number024302
JournalJournal of Applied Physics
Volume122
Issue number2
DOIs
StatePublished - 14 Jul 2017

ASJC Scopus subject areas

  • General Physics and Astronomy

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