title: Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts.
abstract: We performed a detailed investigation of the structural and optical properties of multi-layers of InP/GaAs quantum dots, which present a type II interface arrangement. Transmission electronic microscopy analysis has revealed relatively large dots that coalesce forming so-called quantum posts when the GaAs layer between the InP layers is thin. We observed that the structural properties and morphology affect the resulting radiative lifetime of the carriers in our systems. The carrier lifetimes are relatively long, as expected for type II systems, as compared to those observed for single layer InP/GaAs quantum dots. The interface intermixing effect has been pointed out as a limiting factor for obtaining an effective spatial separation of electrons and holes in the case of single layer InP/GaAs quantum-dot samples. In the present case this effect seems to be less critical due to the particular carrier wavefunction distribution along the structures.
authors.affiliation: Instituto de Física Gleb Wataghin, Unicamp, Campinas-SP, Brazil. iikawa@ifi.unicamp.br
authors.forename: F
authors.initials: F
authors.lastname: Iikawa
authors.forename: V
authors.initials: V
authors.lastname: Donchev
authors.forename: Ts
authors.initials: Ts
authors.lastname: Ivanov
authors.forename: G O
authors.initials: GO
authors.lastname: Dias
authors.forename: L H G
authors.initials: LH
authors.lastname: Tizei
authors.forename: R
authors.initials: R
authors.lastname: Lang
authors.forename: E
authors.initials: E
authors.lastname: Heredia
authors.forename: P F
authors.initials: PF
authors.lastname: Gomes
authors.forename: M J S P
authors.initials: MJ
authors.lastname: Brasil
authors.forename: M A
authors.initials: MA
authors.lastname: Cotta
authors.forename: D
authors.initials: D
authors.lastname: Ugarte
authors.forename: J P
authors.initials: JP
authors.lastname: Martinez Pastor
authors.forename: M M
authors.initials: MM
authors.lastname: de Lima
authors.forename: A
authors.initials: A
authors.lastname: Cantarero