Response Time of Metal-Insulator-Metal Tunnel Junctions

Publisher Website
Google Scholar
Abstract
The current response to a step input voltage is calculated on the basis of the assumption that the decay of each elementary current caused by scattering is slow enough. The exponential decay is not assumed. A general expression for the response time τ is obtained in the case of a square potential-barrier model. When the bias voltage V is so small that e V≪Δ ε, where -e is the electron charge and Δ ε≡\hbar{w(2m/W)1/2}-1 (w is the barrier thickness, m the electron mass and W the height of the potential barrier above the Fermi energy), τ is approximately given by \hbar/(2Δ ε); τ≈1.7×10-15 s and Δ ε≈0.2 eV are obtained when w=20 Å and W=4 eV. At large biases e V≫Δ ε, the current response consists of two parts: one part with the response time of the form \hbar/(e V)+\hbar/Δξ (Δξ is w-independent and Δξ≫Δ ε) and the other part which responds instantaneously to the input voltage.

This publication has 4 references indexed in Scilit: