arXiv subjects

Tobias Særkjær

Publications and source records attributed to Tobias Særkjær.

2 recordsLinked to original sources

arXiv2023

Collective formation of misfit dislocations at the critical thickness for equilibrium nanowire heterostructures

In this work we model the evolution of strain energy during different growth stages of heterostructure nanowires. We find that the minimum energy configuration changes abruptly from fully elastically strained to partially relaxed due to collective formation of a misfit dislocation network. The transition at the critical thickness is associated with a characteristic density of misfits. These insights are gained from a technique developed to simulate misfit dislocations in a finite element framework, incorporating both elastic and plastic relaxation in a stationary heterostructure. We argue that these results have general relevance for mismatched heterostructures.

cond-mat.mtrl-sci↗

arXiv2021

Selective Area Growth Rates of III-V Nanowires

Selective area growth (SAG) of semiconductors is a scalable method for fabricating gate-controlled quantum platforms. This letter reports on the adatom diffusion, incorporation, and desorption mechanisms that govern the growth rates of SAG nanowire (NW) arrays. We propose a model for the crystal growth rates that considers two parameter groups: the crystal growth control parameters and the design parameters. Using GaAs and InGaAs SAG NWs as platform we show how the design parameters such as NW pitch, width, and orientation have an impact on the growth rates. We demonstrate that by varying the control parameters (i.e. substrate temperature and beam fluxes) source, balance, and sink growth modes may exist in the SAG selectivity window. Using this model, we show that inhomogeneous growth rates can be compensated by tuning the design parameters.

cond-mat.mtrl-sci↗