Strain-induced fundamental optical transition in (In,Ga)As/GaP quantum dots

Cédric Robert Robert (1) , Mikhail O. Nestoklon (2) , Katiane Pereira da Silva (3, 4) , Laurent Pedesseau (1) , Charles Cornet (1) , Maria Isabelle Alonso (3) , Alejandro R. Goñi (3, 5) , Pascal Turban (6) , Jean-Marc Jancu (1) , Jacky Even (1) , Olivier Durand (1)

1 FOTON - Fonctions Optiques pour les Technologies de l'informatiON
2 A.F. Ioffe Physical-Technical Institute
3 ICMAB - Institut de Ciència de Materials de Barcelona
4 DC/UFC - Departamento de Computaçãos [Ceará]
5 ICREA - Institució Catalana de Recerca i Estudis Avançats = Catalan Institution for Research and Advanced Studies
6 IPR - Institut de Physique de Rennes

The nature of the ground optical transition in an (In,Ga)As/GaP quantum dot is thoroughly investigated through a million atoms supercell tight-binding simulation. Precise quantum dot morphology is deduced from previously reported scanning-tunneling-microscopy images. The strain field is calculated with the valence force field method and has a strong influence on the confinement potentials, principally, for the conduction band states. Indeed, the wavefunction of the ground electron state is spatially confined in the GaP matrix, close to the dot apex, in a large tensile strain region, having mainly Xz character. Photoluminescence experiments under hydrostatic pressure strongly support the theoretical conclusions.

Keywords: Quantum dots; III-V semiconductors; Hydrostatics; Photoluminescence; Wave functions; Band models; Band structure; Scanning tunneling microscopy; Conduction bands; Nanostructures

Domains: Materials Science [cond-mat.mtrl-sci]

Cédric Robert Robert, Mikhail O. Nestoklon, Katiane Pereira da Silva, Laurent Pedesseau, Charles Cornet, et al.. Strain-induced fundamental optical transition in (In,Ga)As/GaP quantum dots. Applied Physics Letters, 2014, 104 (1), pp.011908. ⟨10.1063/1.4861471⟩. ⟨hal-00941161⟩