Influence of mutual drag of light and heavy holes on conductivity of p-silicon and p-germanium

Conductivity of p-Si and p-Ge is considered for the two-band model with due regard for mutual drag of light and heavy holes. It is shown that for small and moderate temperatures this drag significantly diminishes the drift velocity of light holes and, as a result, the whole conductivity of crystal. The drag effect considered here appears also in the form of non-monotonous dependences of conductivity on temperature and carrier concentration

Instability of 2DEG interacting with drifting 3DEG

Dispersion law is studied for high-frequency longitudinal plasma waves in 2DEG (the plane z = 0), separated by thin dielectric layer from half-limited 3DEG. It is shown that drift of 3DEG provokes for special conditions instability of considered plasma waves

Influence of field dependent form of collision integral on kinetic coefficients

The kinetic equation is turned out in the form that contains collision integral obviously dependent on the value of external electric and magnetic fields. The correspondent calculation of kinetic coefficients shows that for the case considered here they depend evidently on the ratio of average deBroighle wavelength and free-path length. Just here, the real possibility appears to reasonably separate physical kinetics by the classic and non-classic (quantum) ones

Influence of electron-electron drag on piezoresistance of n-Si

Piezoresistance of n-Si is considered with due regard for inter-valley drag. It has been shown that inter-valley drag gains the piezocoefficient and diminishes the mobility. In the region of nondegenerate carriers, the effect of drag increases when the carrier concentration rises and temperature falls

Influence of mutual drag of light and heavy holes on magnetoresistivity and Hall-effect of p-silicon and p-germanium

Hall-effect and magnetoresistivity of holes in silicon and germanium are considered with due regard for mutual drag of light and heavy band carriers. Search of contribution of this drag shows that this interaction has a sufficient influence on both effects

Transport phenomena of two-dimensional band carriers with Dirac-like energetic spectrum

Conductivity of monolayer and bilayer graphene is considered with due regard for mutual drag of band electrons and holes. Search of contribution of the drag to conductivity shows that it sufficiently influences on mobility at high concentrations of carriers, which belong to different groups and have different drift velocities. In bilayer system the mutual drag can even change the direction of partial current. Magnetoresistivity and Hall effect were theoretically investigated for neutral and gated graphene. It is shown that for spatially unlimited neutral graphene Hall effect is totally absent. In gated, exactly monopolar graphene for the same case effect of magnetoresistivity vanishes; here the Hall constant does not involve any relaxation characteristic in contrast to results obtained for the popular method of τ-approximation. It is shown that limited sizes of crystal with monopolar conductivity can be cause for impressive dependence of the Hall constant and magnetoresistivity on the value of external magnetic field

Electron-electron drag in crystals with multivalley band

Mobility of electrons in multivalley bands of Si and Ge is considered with due regard for intervalley drag. It is shown that drag sufficiently diminishes electron mobility at low temperatures. This effect is clearer pronounced in germanium than in silicon

Specific thermoemf and Hall-effect in crystals with monopolar conductivity

The Seebeck coefficient α and Hall constant RH are calculated for monopolar crystal as based of quantum kinetic equation. It is shown that α and RH in the case of simple isotropic band do not depend on relaxation characteristics in contrast to the result obtained for the same crystals by calculations founded on relaxation time approximation

Dependence of the collision integral on electric field

Conductivity of charged band carriers is considered for the case when collision integral evidently depends on electric field. This dependence for the case of scattering by charged impurities results in decrease of carrier conductivity

Electron-electron drag in crystals with a multi-valley band. Magnetoresistivity and Hall-effect

Hall-effect and magnetoresistivity of electrons in multi-valley bands of Si and Ge is considered with due regard for direct intervalley drag. Search of contribution of this drag shows that this interactioin sufficiently changes both effects. Calculated here values substantially differ from consequent those obtained on the base of popular - approximation