Influence of a thin GaAs cap layer on structural and optical properties of InAs quantum dots
Artikel i vetenskaplig tidskrift, 2002

In this letter we investigate the changes in the surface morphology and emission wavelength of InAs quantum dots (QDs) during initial GaAs encapsulation by atomic force microscopy and photoluminescence. The density (2.9×1010 cm-2) and height (7.9±0.4 nm) of the uncapped QDs decrease and saturate at 0.6×1010 cm-2 and 4 nm, respectively, after the deposition of 4 monolayers (MLs) of GaAs. A model for the evolution of surface morphology is proposed. Photoluminescence spectra of the surface dots show a wavelength shift from 1.58 to 1.22 ?m when the GaAs capping layer thickness increases from 0 to 8 MLs.



surface structure

gallium arsenide

semiconductor quantum dots

III-V semiconductors

atomic force microscopy

indium compounds


Fariba Ferdos

Institutionen för mikroelektronik

Shu Min Wang

Institutionen för mikroelektronik

Yongqiang Wei

Institutionen för mikroelektronik

Anders Larsson

Institutionen för mikroelektronik

Mahdad Sadeghi

Institutionen för mikroelektronik och nanovetenskap

Qing Xiang Zhao

Chalmers, Forskargrupp för fysikalisk elektronik och fotonik

Applied Physics Letters

0003-6951 (ISSN) 1077-3118 (eISSN)

Vol. 81 7 1195-7



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