Suppression of dislocations by Sb spray in the vicinity of InAs/GaAs quantum dots

The effect of Sb spray prior to the capping of a GaAs layer on the structure and properties of InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) is studied by cross-sectional high-resolution transmission electron microscopy (HRTEM). Compared to the typical GaAs-capped InAs/GaAs QDs,...

Descripción completa

Detalles Bibliográficos
Autores principales: Dai, Liping, Bremner, Stephen P, Tan, Shenwei, Wang, Shuya, Zhang, Guojun, Liu, Zongwen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer 2014
Materias:
Nano Express
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4051383/
https://www.ncbi.nlm.nih.gov/pubmed/24948897
http://dx.doi.org/10.1186/1556-276X-9-278
Descripción
Sumario:The effect of Sb spray prior to the capping of a GaAs layer on the structure and properties of InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) is studied by cross-sectional high-resolution transmission electron microscopy (HRTEM). Compared to the typical GaAs-capped InAs/GaAs QDs, Sb-sprayed QDs display a more uniform lens shape with a thickness of about 3 ~ 4 nm rather than the pyramidal shape of the non-Sb-sprayed QDs. Particularly, the dislocations were observed to be passivated in the InAs/GaAs interface region and even be suppressed to a large extent. There are almost no extended dislocations in the immediate vicinity of the QDs. This result is most likely related to the formation of graded GaAsSb immediately adjacent to the InAs QDs that provides strain relief for the dot/capping layer lattice mismatch. PACS: 81.05.Ea; 81.07.-b; 81.07.Ta

Ejemplares similares