Gold-Induced grain growth suppression and metallic conductivity in nanocrystalline silicon via pulsed laser annealing
摘要
Pulsed laser annealing (PLA) constitutes a powerful tool for nonequilibrium engineering of thin-film semiconductor properties. In this work, we investigate the impact of deep gold doping on the structural evolution and electronic properties of amorphous silicon films (α-Si:Au) subjected to nanosecond-scale PLA. Gold is shown to play a dual physical role: first, it effectively suppresses crystallite coalescence, limiting crystallite size to 2.3–2.8 nm and preserving a heterophase structure with a high crystalline fraction (up to 78%), as quantitatively corroborated by Raman spectroscopy and the phonon confinement model; second, at concentrations of approximately ~ 5 · 1020 cm-3, gold promotes the formation of a degenerate electron gas, manifesting as metallic-like behavior in the mid-infrared spectral range (2.5–5.0 µm). Key transport parameters—namely, carrier mobility