Metal nanoparticle field-effect transistor

TL;DR

This paper demonstrates a metal nanoparticle-based field-effect transistor using monolayer nanocrystal films, showing tunable Coulomb oscillations and stable operation due to high monodispersity and protective oxide layers.

Contribution

It introduces a novel metal nanocrystal transistor with tunable Coulomb oscillations and long-term stability, achieved through monolayer assembly and dielectric protection.

Findings

Coulomb oscillations observed in metal nanocrystal films

Stable transistor operation over months

Oscillations tunable via nanocrystal size

Abstract

We demonstrate that by means of a local top-gate current oscillations can be observed in extended, monolayered films assembled from monodisperse metal nanocrystals -- realizing transistor function. The oscillations in this metal-based system are due to the occurrence of a Coulomb energy gap in the nanocrystals which is tunable via the nanocrystal size. The nanocrystal assembly by the Langmuir-Blodgett method yields homogeneous monolayered films over vast areas. The dielectric oxide layer protects the metal nanocrystal field-effect transistors from oxidation and leads to stable function for months. The transistor function can be reached due to the high monodispersity of the nanocrystals and the high super-crystallinity of the assembled films. Due to the fact that the film consists of only one monolayer of nanocrystals and all nanocrystals are simultaneously in the state of Coulomb blockade the energy levels can be influenced efficiently (limited screening).