Electron and donor-impurity-related Raman scattering and Raman gain in triangular quantum dots under an applied electric field

The differential cross-section of electron Raman scattering and the Raman gain arecalculated and analysed in the case of prismatic quantum dots with equilateral trianglebase shape. The study takes into account their dependencies on the size of the triangle,the influence of externally applied electri...

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Autores:
Tipo de recurso:
Fecha de publicación:
2016
Institución:
Universidad de Medellín
Repositorio:
Repositorio UDEM
Idioma:
eng
OAI Identifier:
oai:repository.udem.edu.co:11407/2479
Acceso en línea:
http://hdl.handle.net/11407/2479
Palabra clave:
Eigenvalues and eigenfunctions
Electric fields
Nanocrystals
Point defects
Raman scattering
Semiconductor quantum dots
Diagonalizations
Differential cross section
Donor impurities
Electron Raman scattering
Impurity centers
Intermediate state
Linearly polarized
Mesoscopic and nanoscale systems
Electromagnetic wave scattering
Rights
restrictedAccess
License
http://purl.org/coar/access_right/c_16ec
Description
Summary:The differential cross-section of electron Raman scattering and the Raman gain arecalculated and analysed in the case of prismatic quantum dots with equilateral trianglebase shape. The study takes into account their dependencies on the size of the triangle,the influence of externally applied electric field as well as the presence of an ionizeddonor center located at the triangle’s orthocenter. The calculations are made within theeffective mass and parabolic band approximations, with a diagonalization scheme beingapplied to obtain the eigenfunctions and eigenvalues of the x-y Hamiltonian. The incidentand secondary (scattered) radiation have been considered linearly-polarized along they-direction, coinciding with the direction of theapplied electric field. For the case with an impurity center, Raman scattering with theintermediate state energy below the initial state one has been found to show maximumdifferential cross-section more than by an order of magnitude bigger than that resultingfrom the scheme with lower intermediate state energy. The Raman gain has maximum magnitudearound 35 nm dot size andelectric field of 40 kV/cm forthe case without impurity and at maximum considered values of the input parameters for thecase with impurity. Values of Raman gain of the order of up to 104cm-1 are predicted in bothcases. © 2016, EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.