Free-Carrier Infrared Absorption in III-V Semiconductors II. InAs

Abstract

An analysis for the infrared absorption by free carriers in n-type InAs is carried out on the basis of the previous theory developed for n-type InSb, in order to investigate the scattering mechanism. The magnitude of the deformation potential constant E₁ is found to be 10 eV, and it is found that the contribution from acoustical phonons is not important for all samples of Dixon. The impurity concentration is found to be N_imp=11 N_e for the sample A of the smallest carrier concentration: N_e=2.8×10¹⁶cm⁻³, and to be N_imp=N_e for the other samples. Optical phonons make the most important contribution for samples of relatively low carrier concentrations except the sample A, in which the contribution from impurities is comparable to the one from optical phonons.
The presence of an unknown scatterer in the sample A is suggested and a discussion for this is given. A discussion on the screened Coulomb potential used in the calculation of the impurity scattering also is given.