Journal of Nanoparticle Research

, Volume 13, Issue 4, pp 1605–1612

Calculation of the quantum efficiency for the absorption on confinement levels in quantum dots

  • Vladimir Iancu
  • Mihai Razvan Mitroi
  • Ana-Maria Lepadatu
  • Ionel Stavarache
  • Magdalena Lidia Ciurea
Research Paper

DOI: 10.1007/s11051-010-9913-6

Cite this article as:
Iancu, V., Mitroi, M.R., Lepadatu, AM. et al. J Nanopart Res (2011) 13: 1605. doi:10.1007/s11051-010-9913-6

Abstract

The quantum efficiency of the absorption on quantum confinement levels is investigated. This is achieved by modeling the electron confinement in a spherical quantum dot (QD). The confinement levels are calculated using both infinite and finite rectangular quantum wells. The spectral internal quantum efficiency is evaluated within both the models, by computing Einstein’s coefficients for the transitions between confinement levels. The size of QDs (1–3 nm radius) leads to negligible many body effects. The nature of the QD material and of the matrix embedding is taken into account in the finite rectangular quantum well approximation and introduces only a small correction. The temperature dependence of the efficiency is also taken into account. A numerical application is performed for a silicon QD of 2.5 nm radius, embedded in amorphous silica. It is proved that the absorption threshold shifts toward the far infrared limit and that the spectral internal quantum efficiency reaches 4–5% at the threshold.

Keywords

Light absorption Quantum confinement Quantum dots Quantum efficiency Solar cells 

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Vladimir Iancu
    • 1
  • Mihai Razvan Mitroi
    • 1
  • Ana-Maria Lepadatu
    • 2
  • Ionel Stavarache
    • 2
  • Magdalena Lidia Ciurea
    • 2
  1. 1.“Politehnica” University of BucharestBucharestRomania
  2. 2.National Institute of Materials PhysicsMagureleRomania