Confinement effects and hyperfine structure in se doped silicon nanowires

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Silicon nanowires (SiNWs) are crucial in nanoelectronics.
• Understanding impurity behavior in SiNWs is key for device applications.
• Selenium (Se) as a substitutional impurity in silicon presents unique electronic and hyperfine properties.

Purpose of the Study:

• Investigate the electronic properties and hyperfine structure of substitutional selenium in silicon nanowires.
• Analyze the impact of quantum confinement and defect position on Se in SiNWs.
• Explore the formation of chalcogen-hydrogen complexes and their influence.

Main Methods:

• Density functional theory (DFT) calculations.
• Plane-wave pseudopotential techniques for electronic structure.
• Simulation of hydrogen-passivated [001] silicon nanowires up to 2 nm in diameter.

Main Results:

• Substitutional Se in silicon prefers surface-near configurations, potentially forming chalcogen-hydrogen complexes.
• Hyperfine interactions intensify in smaller diameter nanowires, provided surface distortion is minimal.
• Surface effects significantly alter hyperfine parameters based on Se location, enabling impurity site identification.

Conclusions:

• Se impurities in SiNWs exhibit location-dependent electronic and hyperfine properties.
• Quantum confinement and surface interactions critically influence Se behavior in SiNWs.
• Electron paramagnetic resonance can distinguish Se impurity sites within silicon nanowires based on hyperfine spectra.