Origin of cooperative transition of antisite-Arsenic defects in Be-doped low-temperature-grown GaAs layers

• Main Authors: Mohamed, Mohd Ambri, Lam, Pham Tien, Otsuka, N.
• Format: Article
• Language: English
• Published: Elsevier 2013
• Subjects: QC Physics; QD Chemistry; TK7885 Computer engineering
• Online Access: http://irep.iium.edu.my/29881/1/journal_of_crystal_growth.pdf; http://irep.iium.edu.my/29881/; http://dx.doi.org/10.1016/j.jcrysgro.2012.12.070
• Institution: Universiti Islam Antarabangsa Malaysia

A cooperative transition of antisite As (AsGa) defects in Be-doped low-temperature grown GaAs layers was studied by comparing magnetization of samples with different AsGa+ ions concentrations. With the aid of first principle calculations, the origin of cooperative transitions was shown to be due to a lattice strain which results in elastic interactions among AsGa defects. A change in magnetizations is induced by large lattice distortions during transition of AsGa defects from substitutional sites to interstitial sites. The calculation of electron states of an AsGa atom with a shallow acceptor Be atom show that at the transition, an AsGa+ ion is displaced to the interstitial site and becomes a neutral atom, leading to a magnetization annihilation.