Formation and phase transformation of Bicontaining QD-like clusters in annealed GaAsBi

Wu M, Luna E, Puustinen J, Guina M, Trampert A (2014)

Publication Language: English

Publication Status: Published

Publication Type: Journal article

Publication year: 2014

Journal

Nanotechnology Institute of Physics: Hybrid Open Access

Publisher: IOP PUBLISHING LTD

Book Volume: 25

Journal Issue: 20

DOI: 10.1088/0957-4484/25/20/205605

Abstract

We report the formation and phase transformation of Bi-containing clusters in GaAs1-x Bi-x epilayers upon annealing. The GaAs1-x Bi-x layers were grown by molecular beam epitaxy under low (220 degrees C) and high (315 degrees C) temperatures and subsequently annealed using different temperatures and annealing times. Bi-containing clusters were identified only in the annealed samples that were grown at low temperature, revealing a relatively homogeneous size distribution. Depending on the annealing temperature and duration, the clusters show different sizes ranging from 5 to 20 nm, as well as different crystallographic phase, being coherently strained zincblende GaAs1-x Bi-x (zb Bi-rich Ga(As, Bi)) clusters or rhombohedral pure Bi (rh-Bi) clusters. We found that: (1) the formation of the zb Bi-rich Ga(As, Bi) clusters is driven by the intrinsic tendency of the alloy to phase separately and is mediated by the native point defects present in the low temperature grown epilayers; (2) the phase transformation from zb Bi-rich Ga (As, Bi) to rh-Bi nucleates in zincblende {111} planes and grows until total consumption of Bi in the GaAs matrix. We propose a model accounting for the formation and phase transformation of Bi-containing clusters in this system. Furthermore, our study reveals the possibility to realize self-organized zb Bi-rich Ga(As, Bi) clusters that can exhibit QD-like features.

Authors with CRIS profile

Mingjian Wu Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung)

Additional Organisation(s)

Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

Involved external institutions

Tampere University of Technology FI Finland (FI) Paul-Drude-Institut für Festkörperelektronik - Leibniz-Institut im Forschungsverbund Berlin e.V. DE Germany (DE)

How to cite

APA:

Wu, M., Luna, E., Puustinen, J., Guina, M., & Trampert, A. (2014). Formation and phase transformation of Bicontaining QD-like clusters in annealed GaAsBi. Nanotechnology, 25(20). https://dx.doi.org/10.1088/0957-4484/25/20/205605

MLA:

Wu, Mingjian, et al. "Formation and phase transformation of Bicontaining QD-like clusters in annealed GaAsBi." Nanotechnology 25.20 (2014).

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