Metal nanoparticle field-effect transistor

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).

Metal nanoparticle film–based room temperature Coulomb transistor

“…This fabrication route is not only simple and scalable but also especially highly tunable. On the one hand, the particles can be adjusted in size and shape as well as their interparticle spacing ( 17 , 18 , 30 , 32 ). On the other hand, the monolayer can be patterned by lithography to define stripe-shaped nanoparticle arrays.…”

“…In the pronounced main minimum of the gate-voltage sweep, not only the energy-level configuration is most unfavorable for transport, but also the overall electric-field gradient between the three contacts is disadvantageous for elastic tunneling. Depending on the exact location of the gate electrode under the channel and on the gate width, a simple model ( 32 ) suggests that this main minimum is at V gate ≈ V SD /2. At this gate voltage, the linear potential gradient is least disturbed and remains very unfavorable for resonant tunneling so that the current is minimal.…”

Metal Domain Size Dependent Electrical Transport in Pt-CdSe Hybrid Nanoparticle Monolayers

“…2 The solution processability of nanoparticle building blocks makes them particularly attractive for applications such as photovoltaics, [3][4][5][6] light emitting diodes, [7][8][9] as well as chemical sensing and photodetection. [10][11][12][13][14] The fundamental electrical properties of single material systems consisting of either semiconductor or metal nanoparticles have been studied especially with respect to quantum-mechanical coupling phenomena, [15][16][17][18][19][20] Coulombblockade behavior, 21,22 transistor characteristics, [23][24][25] and photo conductivity. 20,26,27 Nanoparticles prepared by colloidal chemistry can be arranged into ordered arrays by a variety of methods.…”

Electrical transport through self-assembled colloidal nanomaterials and their perspectives

“…If a dielectric layer is deposited onto the metal nanoparticle monolayer a third, gate electrode can be defined on top of it by electron-beam lithography. The application of a gate voltage can then modulate the current through the film due to a shift in the Coulomb energy levels of the individual nanoparticles leading to transistor-type characteristics [126]. The Coulomb charging energy of the individual nanoparticles adopts a similar function like the semiconductor bandgap.…”