title: Effect of Morphology on the Electrical Resistivity of Silver Nanostructure Films.
abstract: The relatively high temperatures (>200 °C) required to sinter silver nanoparticle inks have limited the development of printed electronic devices on low-cost, heat-sensitive paper and plastic substrates. This article explores the change in morphology and resistivity that occurs upon heating thick films of silver nanowires (of two different lengths; Ag NWs), nanoparticles (Ag NPs), and microflakes (Ag MFs) at temperatures between 70 and 400 °C. After heating at 70 °C, films of long Ag NWs exhibited a resistivity of 1.8 × 10-5Ω cm, 4000 times more conductive than films made from Ag NPs. This result indicates the resistivity of thick films of silver nanostructures is dominated by the contact resistance between particles before sintering. After sintering at 300 °C, the resistivity of short Ag NWs, long Ag NWs, and Ag NPs converge to a value of (2-3) × 10-5Ω cm, while films of Ag MFs remain ∼10× less conductive (4.06 × 10-4Ω cm). Thus, films of long Ag NW films heated at 70 °C are more conductive than Ag NP films sintered at 300 °C. Adding 10 wt % nanowires to a film of nanoparticles results in a 400-fold improvement in resistivity.
authors.affiliation: Department of Chemistry, Duke University , 124 Science Drive, Box 90354, Durham, North Carolina 27708, United States.
authors.forename: Ian E
authors.initials: IE
authors.lastname: Stewart
authors.affiliation: Department of Chemistry, Duke University , 124 Science Drive, Box 90354, Durham, North Carolina 27708, United States.
authors.forename: Myung Jun
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Duke University , 124 Science Drive, Box 90354, Durham, North Carolina 27708, United States.
authors.forename: Benjamin J
authors.identifier: http://orcid.org/0000-0003-0055-9018
authors.initials: BJ
authors.lastname: Wiley
keywords: electrical resistivity; silver microflakes; silver nanoparticles; silver nanowires; sintering