ABSTRACT

A film fabricated by the assembling of nanoparticles that retain, at least partially, their individuality is expected to show substantially different structural and functional properties compared to the case where atoms or molecules are used as building blocks. Although films assembled with metallic clusters or nanoparticles have been predicted to have unusual functional properties, it has been tacitly assumed that cluster-assembled metallic films have the same conduction behavior observed for polycrystalline metallic thin films grown from atoms. Unexpectedly, in the last decade, several studies showed that nanogranular metallic films show a non-linear electric behavior, substantially different from their polycrystalline counterparts. Here we review and discuss the electrical transport properties of cluster-assembled films. Our aim is to provide a background and a common language for the systematic investigation and exploitation of nanogranular metallic thin films where the extremely high density of defects and grain boundaries causes the departure from ohmic behavior. We will focus on the non-linear electrical conduction and resistive switching relevant for neuromorphic applications.

摘要

与将原子或分子用作结构单元的情况相比，通过组装至少部分保留其个体性的纳米颗粒而制备的膜有望显示出显着不同的结构和功能特性。尽管已经预测了用金属簇或纳米颗粒组装的膜具有不同寻常的功能特性，但已经默认地认为，簇组装的金属膜具有与从原子生长的多晶金属薄膜所观察到的相同的导电行为。出乎意料的是，在最近的十年中，多项研究表明，纳米颗粒金属膜表现出非线性的电行为，与多晶金属膜有很大不同。在这里，我们回顾和讨论簇组装薄膜的电输运特性。我们的目标是为纳米颗粒金属薄膜的系统研究和开发提供背景和通用语言，其中极高密度的缺陷和晶界导致偏离欧姆行为。我们将专注于与神经形态应用相关的非线性导电和电阻切换。