The segregation and oxidation of silicon on Pt(111), or: The question of the “platinum oxide”

Auger spectroscopic study of the surface composition of Pt/Sn alloys in ultrahigh vacuum and in the presence of oxygen and hydrogen

A first-principles theory of carrier distribution in the presence of an electric field of arbitrary strength, which takes into account the quantum-mechanical field-broadening, is described under conditions that the acoustic-phonon scattering is the dominant mechanism of scattering. The general expression of the mobility so obtained reduces to its Ohmic value for vanishing small electric fields, is a quadratic function of electric field in the warm-electron regime, and varies inversely with the electric field at sufficiently high electric fields (hot-electron regime). A saturation current is obtained in the high-field limit, when electron mobility is limited solely by the field-broadening effect; the saturation velocity being comparable to the thermal velocity of an electron. The hot-electron temperature, defined in terms of average energy of an electron, is equal to the lattice temperature in the Ohmic regime, rises quadratically with the increasing electric field in the warm-electron regime, and rises linearly in the hot-electron regime. These results are in agreement with those of experiments on n-Germanium.

https://iopscience.iop.org/article/10.1143/JJAP.24.537/pdf

High-Field Distribution and Mobility in Semiconductors

Surface Debye-Waller factors for Cr(100) and Mo(100)

Electric Conductivity of Hot Carriers in Si and Ge

The characteristics of hot-carrier magnetoresistance for small magnetic fields are studied with the assumptions: (a) The constant-energy surfaces are spherical and carriers are scattered by acoustic and optical phonons; and (b) the constant-energy surfaces are ellipsoidal and the scattering is due to acoustic, optical, and intervalley phonons. It is shown that for a spherical constant-energy-surface model the magnetoresistance has a small negative value decreasing with increasing field, and the magnetoresistance coefficient is independent of the field if the scattering is by acoustic phonons alone. On the other hand, for predominant optical-phonon scattering the magnetoresistance and also the magnetoresistance coefficient are positive and decrease with increasing field. In the case of many-valley band structure as in $n$-type germanium, the characteristics of magnetoresistance and magnetoresistance coefficient for predominant acoustic-phonon scattering are the same as for a spherical constant-energy-surface model, but the sign is positive and the values are larger. The variation of magnetoresistance and magnetoresistance coefficient for predominant optical-phonon scattering when the electric field is in the [100] direction is similar to that for a spherical constant-energy-surface model, but the values are higher and the characteristic varies in details. For the [111] direction of the field, on the other hand, the magnetoresistance decreases with the field, but the magnetoresistance coefficient increases with the field. The values of magnetoresistance calculated from theory, assuming acoustic- and optical-phonon scattering, are found to agree closely with the experimental results. The inclusion of the effects of intervalley scattering leads to a further improvement in the agreement.

Hot-Carrier Magnetoresistance

The longitudinal magnetoresistance and Hall mobility of 5‐Ω·cm n‐type germanium have been measured for electric fields applied in the (111) direction up to 4 kV/cm. It has been found that (i) longitudinal magnetoresistance at a particular electric field decreases with an increase in the magnetic field, (ii) for small magnetic fields the longitudinal magnetoresistance decreases with an increase in the electric field, and (iii) the Hall mobility and the ratio of Hall mobility to the conductivity mobility decrease with an increase in the electric field.The experimental value for fields above 1 kV/cm are found to agree with the theoretical values calculated with the assumptions that (i) the scattering is due to the acoustic, optical, and intervalley phonons, (ii) the average energy of the electrons is much larger than that of the optical phonons, (iii) the intervalley phonons affect only the carrier repopulation in the different valleys, and (iv) the value of the optical‐phonon deformation potential constant ...

Longitudinal Magnetoresistance and Hall Mobility of n‐Type Germanium at High Electric Fields

Hall mobility and carrier repopulation of n-type silicon at high electric fields

The velocity distribution function of hot carriers in a semiconductor in high magnetic fields is obtained correct up to the second approximation. The Hall mobility and magnetoresistance are calculated from this distribution function. It is found that the Hall mobility is not very dependent on the magnetic field and that the hot-carrier magnetoresistance would be larger than the small field magnetoresistance.

https://iopscience.iop.org/article/10.1088/0370-1328/81/4/315/pdf

Hall Mobility and Magnetoresistance of Semiconductors due to Hot Carriers in High Magnetic Fields

The distribution function of carriers in a high electric and a simultaneous magnetic field is derived taking into consideration the effect of both acoustic and optical phonon scattering Using this distribution function, expressions for the Hall mobility are obtained These expressions indicate, and the numerical results calculated with the parameter values of n-type germanium also verify, that if optical phonon scattering occurs in addition to acoustic phonon scattering the value of the Hall mobility is increased The Hall mobility is also found to increase with magnetic field

http://iopscience.iop.org/article/10.1088/0370-1328/82/5/310/pdf

H. Paria

Papers

Hot-Carrier Magnetoresistance

Longitudinal Magnetoresistance and Hall Mobility of n‐Type Germanium at High Electric Fields

Hall mobility and carrier repopulation of n-type silicon at high electric fields

Hall Mobility and Magnetoresistance of Semiconductors due to Hot Carriers in High Magnetic Fields

Effect of optical phonon scattering on hot electron hall mobility of semiconductors