Self-Assembly of Tensile-Strained Ge Quantum Dots on InAlAs(111)A
A recently developed growth technique enables the self-assembly of defect-free quantum dots on (111) surfaces under large tensile strains. We demonstrate the use of this approach to synthesize germanium (Ge) quantum dots on In0.52Al0.48As(111)A with >3% residual tensile strain. We show that the size and areal density of the tensile-strained Ge quantum dots are readily tunable with growth conditions. We also present evidence for an unusual transition in the quantum dot growth mode from Stranski-Krastanov to Volmer-Weber as we adjust the substrate temperature. This work positions Ge quantum dots as a promising starting point for exploring the effects of tensile strain on Ge’s band structure.
Sautter, Kathryn E.; Schuck, Christopher F.; Garrett, Trent A.; Weltner, Ariel E.; Vallejo, Kevin D.; Ren, Dingkun; Liang, Baolai; Grossklaus, Kevin A.; Vandervelde, Thomas E.; and Simmonds, Paul J. (2020). "Self-Assembly of Tensile-Strained Ge Quantum Dots on InAlAs(111)A". Journal of Crystal Growth, 533, 125468. https://doi.org/10.1016/j.jcrysgro.2019.125468