title: Quantum-dot size and thin-film dielectric constant: precision measurement and disparity with simple models.
abstract: We study the dielectric constant of lead sulfide quantum dot (QD) films as a function of the volume fraction of QDs by varying the QD size and keeping the ligand constant. We create a reliable QD sizing curve using small-angle X-ray scattering (SAXS), thin-film SAXS to extract a pair-distribution function for QD spacing, and a stacked-capacitor geometry to measure the capacitance of the thin film. Our data support a reduced dielectric constant in nanoparticles.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Darcy D W
authors.initials: DD
authors.lastname: Grinolds
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Brown
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Harris
authors.forename: Vladimir
authors.initials: V
authors.lastname: Bulovic
authors.forename: Moungi G
authors.initials: MG
authors.lastname: Bawendi
keywords: Dielectric constant; PbS; SAXS; capacitance; quantum dot