GaAs1-xBix growth on Ge: anti-phase domains, ordering, and exciton localization
| Autor: | Arūnas Krotkus, Martynas Skapas, Evelina Dudutienė, Rafal Jakiela, Sandra Stanionytė, Viktorija Strazdienė, Arnas Naujokaitis, Vaidas Pačebutas, Viliam Vretenár, Mária Čaplovičová, A. Geižutis, Tadas Paulauskas, Bronislovas Čechavičius |
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| Rok vydání: | 2020 |
| Předmět: |
Copper oxide
Photoluminescence Materials science Infrared Band gap Science Exciton Alloy 02 engineering and technology engineering.material 01 natural sciences Article law.invention chemistry.chemical_compound Nanoscience and technology law Phase (matter) 0103 physical sciences 010302 applied physics Multidisciplinary Condensed matter physics 021001 nanoscience & nanotechnology chemistry engineering Medicine Scanning tunneling microscope 0210 nano-technology |
| Zdroj: | Scientific Reports, Vol 10, Iss 1, Pp 1-12 (2020) Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | The dilute bismide alloy GaAs1-xBix has drawn significant attention from researchers interested in its fundamental properties and the potential for infrared optoelectronics applications. To extend the study of bismides, molecular-beam heteroepitaxy of nominally 1.0 eV bandgap bismide on Ge substrates is comprehensively investigated. Analysis of atomic-resolution anti-phase domain (APD) images in the direct-epitaxy revealed a high-density of Ga vacancies and a reduced Bi content at their boundaries. This likely played a key role in the preferential dissolution of Bi atoms from the APD interiors and Bi spiking in Ge during thermal annealing. Introduction of GaAs buffer on offcut Ge largely suppressed the formation of APDs, producing high-quality bismide with single-variant CuPtB-type ordered domains as large as 200 nm. Atomic-resolution X-ray imaging showed that 2-dimensional Bi-rich (111) planes contain up to x = 9% Bi. The anomalously early onset of localization found in the temperature-dependent photoluminescence suggests enhanced interactions among Bi states, as compared to non-ordered samples. Growth of large-domain single-variant ordered GaAs1-xBix films provides new prospects for detailed analysis of the structural modulation effects and may allow to further tailor properties of this alloy for optoelectronic applications. |
| Databáze: | OpenAIRE |
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