Hole Transport in Polar Semiconductors

Abstract

The transport properties of holes in cubic semiconductors have been studied with a Monte Carlo technique taking into account polar scattering within and between the two valence bands degenerate at k = 0. The predominant p-like symmetry of the valence band wave functions has been found to enhance the polar ohmic mobility of about a factor two with respect to the case in which i t is neglected. The comparison between theoretical results and experimental data evidences the dominant importance of polar scattering mechanism for a typical 11-VI compound (CdTe) in the region of temperatures between 100 and 400 O K .On the contrary, this scattering mechanism alone cannot explain the low field transport of a typical 111-V compound (GaAs) in the same temperature range, according to its lower ionicity.

On Hall scattering factors for holes in GaAs

“…11 also give Hall factors on the order of 1.6-2.0 for pure material. [4][5][6] Thus, at 296 K, theory predicts that r n Ӎ1 and r p Ӎ2 over the range of concentrations presented here.…”

“…Although the individual band Hall factors, r pl and r ph , respectively, are also in the range 1.0-1.2 ͑if the bands are noninteracting͒, the combined Hall factor can be much larger. 4 A few calculations have included much ͑although not all͒ of the necessary complexity of hole transport in GaAs; [4][5][6][7][8] Wiley has given an excellent discussion of the various problems involved. 9 Values of r p determined in most of the calculations are significantly larger than unity, ranging from 1.25 to greater than 2.…”

Nonequilibrium hole relaxation dynamics in an intrinsic semiconductor

“…Furthermore, because of the different energy of the TO and LO phonons, multiple scattering contributes to energy redistribution between holes, especially at low densities. The nonpolar scattering rates were derived by Costato and Reggiani 36 and we have used the measured optical deformation potential d 0 ϭ48 eV. 37 As the electron-LO phonon interaction involves small wave-vector exchanges and, for the investigated carrier density range, is thus sensitive to the screening model, dynamic screening in the plasmon pole approximation has been used.…”

Two-band analysis of hole mobility and Hall factor for heavily carbon-doped p-type GaAs

“…7,23 Although this decoupled approximation has been used in many cases, 24,25 it has proved to be extremely poor in the case of phonon scattering. 6,26,27 In order to include the presence of interband scattering, a more rigorous formula was presented, 28 and later, as a simplified version of this formula, a ''partial coupling approximation'' was proposed. 7 However there has not been a completely general formulation for the interacting two-band system in the isotropic-band regime.…”