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Shape and Composition Evolution in an Alloy Core-Shell Nanowire Heterostructure Induced by Adatom Diffusion
Delong Han1, Wenlei Tang2, Naizhang Sun2
1Shandong Computer Science Center (National Supercomputer Center in Jinan), Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China.
Nanomaterials (Basel, Switzerland)
|June 10, 2023
Summary
Adatom diffusion significantly influences the shape and composition of alloy core-shell nanowires, crucial for optoelectronic devices. Understanding these kinetic processes is key to controlling nanowire growth and properties.
Area of Science:
- Materials Science
- Nanotechnology
- Computational Physics
Background:
- Core-shell nanowire heterostructures are vital components in advanced optoelectronic devices.
- Controlling the morphology and composition of these heterostructures is essential for device performance.
Purpose of the Study:
- To develop and utilize a growth model for alloy core-shell nanowire heterostructures.
- To investigate the influence of adatom diffusion on shape and composition evolution during nanowire growth.
Main Methods:
- Numerical solution of transient diffusion equations using the finite element method.
- Incorporation of diffusion, adsorption, desorption, and incorporation kinetics of adatoms.
- Modeling of moving boundaries to account for sidewall growth.
Main Results:
- Adatom diffusion leads to position-dependent and time-dependent adatom concentrations.
- Nanowire shell morphology, including thickness distribution and contact angle, is strongly dependent on flux impingement angle.
- Composition profiles are non-uniform along nanowire and shell growth directions due to adatom diffusion.
Conclusions:
- The kinetic model successfully elucidates the role of adatom diffusion in shaping alloy core-shell nanowires.
- Systematic investigation reveals the impact of diffusion length, adatom lifetime, and component ratios on evolution.
- The model provides insights for growing alloy group-IV and group III-V core-shell nanowire heterostructures.
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