Polyol synthesis of silver nanoparticles and the effect of their crystalline state on low-temperature sintering performance
Year: 2026
Type: article
Abstract: Reducing the sintering temperature and electrical resistivity of silver nanoparticles (Ag NPs) represents a critical challenge for advanced flexible electronics. Herein, two quasi-spherical Ag NPs samples (denoted P and S) with drastically distinct sintering behavior were synthesized via the polyol approach. Structural characterization verified that Sample P was principally composed of polycrystalline particles bounded by (111), (200), and (220) crystal planes with residual Ag⁺ species, whereas Sample S was dominated by single-crystalline particles predominantly enclosed by (111) facets. Relative to polycrystalline counterparts, single-crystalline particles possessed smaller crystallite size and lower micro-strain. After screen-printing and sintering at 140 °C for 1 h, the single-crystal Ag NPs film on polyimide (PI) substrate delivered a resistivity of 2.1×10-5 Ω·cm, remarkably lower than 2.2×10-4 Ω·cm for polycrystalline Sample P. Mechanistically, sintering of single-crystal Ag NPs proceeded via bulk and surface diffusion pathways, while polycrystalline particles underwent grain-boundary diffusion, giving rise to substantial micro-strain elevation. Intense electron scattering induced by grain boundaries, defects, and pores was identified as the predominant origin for the elevated resistivity of polycrystalline sintered films. After sintering at 200 °C for 1 hour, the single-crystal Ag NPs film achieved a porosity of 0.9% and resistivity of 9.0×10-6 Ω·cm, approaching the level of bulk silver (1.59×10-6 Ω·cm), in sharp contrast to 7% porosity and 8.4×10-5 Ω·cm resistivity for the polycrystalline Ag NPs film. These findings confirmed that crystalline state governed the sintering performance discrepancy between single- and polycrystalline Ag NPs.
Institution: Beijing Institute of Graphic Communication
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,640
OpenAlex ID: W7212247933