Importance of interface sampling for extraordinary resistance effects in metal semiconductor hybrids

Abstract

The magnitude of the extraordinary resistance change in metal semiconductor hybrid structures at 300 K under either magnetic field or tensile strain is known to depend strongly on geometry. In particular, there exists a range of optimal geometries for which the change in resistance under the external perturbation is maximized. Here we numerically solve Laplace's equation for circular hybrids in which the local resistivity is perturbed, and we show that within the range of optimal geometries ͑i͒ the metal-semiconductor interface is maximally sampled by the injected current and ͑ii͒ there is an observed crossover from semiconductor-like to metal-like conduction. Extraordinary resistance changes in metal semiconductor hybrids are thus considered to be interfacial effects.

Giant Room-Temperature Piezoresistance in a Metal-Silicon Hybrid Structure

“…The hybrid resistivity weighting function (HRWF) provides a quantitative measure of the contribution that each point in the hybrid makes to the zero stress resistance [20]; its value at any given point in space depends on the device geometry together with the current and voltage lead positions. Figures 4(a) 4 cm ÿ1 in amplitude as the conductivity perturbation.…”

Finite-Element Modelling and Analysis of Hall Effect and Extraordinary Magnetoresistance Effect

“…This results in a redistribution of the current from the metal shunt into the semiconductor causing a resistance increase. It is important to note that the fundamental principle of EMR is the change of the current path in the hybrid structure upon application of a magnetic field rather than the change of magnetoconductivity σ of either the semiconductor or the metal [4][5]. This effect has drawn much attention due to its potential advantages over other solid-state magnetic field sensors [6][7][8][9].…”

Geometric factors in the magnetoresistance of n-doped InAs epilayers

“…been demonstrated theoretically that the extraordinary MR is essentially an interfacial effect. 11 There are other origins for MR in systems involving ferromagnetic materials, such as in multilayers consisting of alternating ferromagnetic and non-ferromagnetic layers, 12,13 or in colossal magnetoresistive materials, 14,15 and in these cases, the MR is strongly linked to the scattering being dependent on the spin of the carrier.…”