Transition Mechanism of InAs Quantum Dot to Quantum Ring Revealed by Photoluminescence Spectra

Author

Dai, Jong-Horng ; Lee, Jheng-Han ; Lee, Si-Chen

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei

Volume

20

Issue

16

fYear

2008

Firstpage

1372

Lastpage

1374

Abstract

The transition mechanism of InAs quantum dot (QD) to quantum ring (QR) was investigated. After the growth of InAs QDs, a thin layer of GaAs was overgrown on the InAs QD and the sample was annealed at the same temperature for a period of time. It was found that the central part of the InAs islands started to out diffuse and formed ring shape only after a deposition of a critical thickness (1 ~ 2 nm) of GaAs capped layer depending on the size of InAs QDs. This phenomenon was revealed by photoluminescence measurement and atomic force microscopy image. It is suggested that the strain energy provided by the GaAs overgrown layer is responsible for the InAs to diffuse out of the island to form QR.

Keywords

III-V semiconductors; annealing; indium compounds; photoluminescence; semiconductor quantum dots; InAs; InAs quantum dot; atomic force microscopy; critical thickness; photoluminescence spectra; quantum ring; strain energy; Annealing; Atomic force microscopy; Atomic layer deposition; Atomic measurements; Force measurement; Gallium arsenide; Photoluminescence; Quantum dots; Shape; Temperature; Blue-shifted; outward diffusion; quantum dot (QD); quantum ring (QR);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2008.926813

Filename

4579310