• Sarma, D. D.
• Nag, Angshuman
• Jagadeeswararao, Metikoti
• Pal, Somnath

Abstract

<jats:title>Abstract</jats:title><jats:p>Sn<jats:sup>4+</jats:sup>‐doped In<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> (ITO) is a benchmark transparent conducting oxide material. We prepared ligand‐free but colloidal ITO (8 nm, 10 % Sn<jats:sup>4+</jats:sup>) nanocrystals (NCs) by using a post‐synthesis surface‐modification reaction. (CH<jats:sub>3</jats:sub>)<jats:sub>3</jats:sub>OBF<jats:sub>4</jats:sub> removes the native oleylamine ligand from NC surfaces to give ligand‐free, positively charged NCs that form a colloidal dispersion in polar solvents. Both oleylamine‐capped and ligand‐free ITO NCs exhibit intense absorption peaks, due to localized surface plasmon resonance (LSPR) at around <jats:italic>λ</jats:italic>=1950 nm. Compared with oleylamine‐capped NCs, the electrical resistivity of ligand‐free ITO NCs is lower by an order of magnitude (≈35 mΩ cm<jats:sup>−1</jats:sup>). Resistivity over a wide range of temperatures can be consistently described as a composite of metallic ITO grains embedded in an insulating matrix by using a simple equivalent circuit, which provides an insight into the conduction mechanism in these systems.</jats:p>

Topics

• impedance spectroscopy
• dispersion
• surface
• grain
• resistivity
• composite