Observation and study of the negative magnetoresistance in porous silicon

Electrical conductance and magnetoconductance effect on n-type porous silicon: Contribution of weak localization correction

“…Furthermore, the conduction in the PS/Si heterojunction is due to bulk processes in PS rather than to junction proprieties [8]. As a consequence, we assume that the electrical transport properties of the PS/Si heterojunction are governed by the contribution of Si nanocrystallites [3].…”

“…For a finite size conductor, electronic transport is characterized by a conductance which is related to the conductivity by the usual form G = rS/L for a sample with a cylindrical geometry of length L and section S. From Eq. (1), one can deduce that for a wire having a length L and a section S, the conductance can be expressed as follow [3]:…”

“…Furthermore, Yakimov present the observation of the negative MR in porous amorphous silicon for transverse low magnetic field (60.25 T) at room temperature, this effect is related to the magnetic field stimulated suppression of destructive interference in the 1-D system [8]. Observation of positive MC in n-type PS and p-type PS at room temperature has been intensively studied and can be interpreted as a WL theory [9,3]. In addition, Wang observed large positive MC at room temperature in disordered pregraphitic carbon nanofiber and that this effect can still be described using WL regime [10].…”

“…The explanation of the reduction of the conductance is a result of the interplay between conventional electron transport (the Drude-Boltzmann conductance) and the quantum interference effect. Quantum corrections to the conductance of disordered systems at room temperatures have been intensively studied [2,3] and the resistivity measurement can be interpreted by weak localization (WL) theory. The WL theory can be understood in terms of quantum interference between two waves propagating by multiple scatters along the same path but in opposite directions [3].…”

“…Quantum corrections to the conductance of disordered systems at room temperatures have been intensively studied [2,3] and the resistivity measurement can be interpreted by weak localization (WL) theory. The WL theory can be understood in terms of quantum interference between two waves propagating by multiple scatters along the same path but in opposite directions [3]. After the discovery of WL, the theory of the magnetoresistance (MR) was elaborated and study in term of WL regime at to near room temperature [4], The WL theory was established that negative MR (or positive MC) occurs due to the destruction of the quantum corrections to the conductance by the external magnetic field which affects the phase coherence.…”