Electron Transport and Charge Memory Effects in Metal-Dielectric Nanocomposites
Abstract
The purpose of this work is to study the mesoscopic limits of conductivity in granulated materials like metal-dielectric nanocomposites and to reveal the major design features of mesoscopic transistor (and charge memory device) made of these materials. Thin composite Cu:SiO2 films containing 2-3 nm Cu granules were fabricated and temperature dependencies of conductivity were measured (in dielectric regime) as function of Cu content and the sample size The experimental results are analyzed using newly developed numerical model of conductivity which deals with the network of tunneling resistance between randomly arranged small metallic balls, accounts for Coulomb interaction between charged balls, and essentially incorporates screening effects. It is found that the experimental conductivity of all the samples follows the universal "1/square root T" law at low temperatures (T<100K) which is treated as the manifestation of Coulomb gap in the density of states of composite material. Both simulations and experiment show that the mesoscopic limit of the composite sample size is about 20-30 nm at T approx. 300K (and approx. 50 nm at 30K). We argue that with such small samples it should be possible to implement the room temperature single-electron transistor device by applying the electric field perpendicular to the current chain.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1999
- Accession Number
- ADA372482
Entities
People
- D. A. Zakheim
- I. V. Rozhansky
- S. A. Gurevich
- V. A. Zabelin
- V. I. Scopina
Organizations
- Russian Academy of Sciences