Electron Mobility in CdSexTe1-x (x = 0.25) Solid Solution: Ab Initio Calculation

O.P Malyk,S.V Syrotyuk

doi:10.15330/pcss.20.4.338-344

Abstract

In this paper an assessment of the quality of a solid solution of CdSexTe1-x is done by study of its transport properties. The description of the kinetic phenomena is carried on the base of the wave function and self-consistent potential for solid solution CdSexTe1-x (x = 0.25) which were determined from the first principles using the projector augmented waves as implemented in the ABINIT code. The scattering processes were considered in the framework of short-range scattering models where the electron interaction with polar and nonpolar optical phonons, piezoelectric and acoustic phonons, static strain centers, neutral and ionized impurities was taken into account. The transition matrix elements were obtained by integration over the unit cell using three-dimensional B-spline interpolation. For crystals with impurity concentration 5.6´1015 - 5´1018 cm-3 the temperature dependences of electron mobility and Hall factor in the range 15 - 1200 K are calculated. The theoretical curves obtained in the short-range approach differ qualitatively and quantitatively from those obtained within the long-range models in relaxation time approximation.

Highlights

In this paper an assessment of the quality of a solid solution of CdSexTe1-x is done by study of its transport properties
The description of the kinetic phenomena is carried on the base of the wave function and self-consistent potential for solid solution CdSexTe1-x (x = 0.25) which were determined from the first principles using the projector augmented waves as implemented in the ABINIT code
The scattering processes were considered in the framework of short-range scattering models where the electron interaction with polar and nonpolar optical phonons, piezoelectric and acoustic phonons, static strain centers, neutral and ionized impurities was taken into account

Summary

Theory

First we put that the lattice constant corresponding to the composition x=0.25 of the solid solution equal to a0 = 6.38 Å. This value was used to calculate the wave functions and self-consistent potentials in CdTe and CdSe crystals. These wave functions and self-consistent potentials were determined from the first principles on the base of projector augmented waves (PAW) [21]. The PAW basis functions have been generated by means of the AtomPAW 22 code for the following valence states: {5s25p04d10} for Cd, {4s25s24p25p4 } for Te and {4s24p4} for Se, respectively. The exchange-correlation potential was selected in the form of PBE0 [23,24,25,26] obtained from the functional of the exchange-correlation energy

CdSeTe

AP2O e4 ε0 2a0 8 G

Temperature dependences of electron mobility and Hall factor

Conclusion