The synthesis of monodispersed AgBiS2 quantum dots with a giant dielectric constant

Abstract

Monodispersed AgBiS2 quantum dots of high phase purity with an average diameter of 8.5 ± 1.2 nm have been synthesized for the first time by a hot-injection method. The optical band gap of the well-dispersed quantum dots is ∼2.67 eV, indicating a strong quantum confinement. The quantum dot pellet shows a large dielectric constant of the order of 105. Independent measurements demonstrate that the large grain boundary resistance and capacitance contribute to the giant dielectric constant. Monodispersed AgBiS2 quantum dots may find significant implications in high-k applications.