Faraday rotation analysis of HgCdTe

Abstract

Faraday rotation was measured in liquid-phase epitaxial (LPE) Hg, , Cd, Te (x % 0.22) at CO, laser photon energies over the temperature range of 77 K to 300 K for magnetic fields up to 16 kG. We find that t h e Faraday rotation is composed of free-carrier, interband and spin-induced contributions. At 77 K, the interband and spin contributions dominate, resulting in large observed Faraday rotation, i.e. of the order of 10'deg cn-' kG-'. All three contributions are needed to interpret the temperature and magnetic field dependence of the Faraday rotation in our samples. Resonant behaviour observed in the rotation angle is successfully described by impurity-to-band magneto-optical absorption. W e conclude that Faraday rotation could serve as a viable technique for the non-contact measurement of carrier concentration in Hg,,Cd,Te.

Measurement of electron effective mass ratios in Hg 1-x Cd x Te for 0.20 ⩽ x ⩽ 0.30 between 77K and 296K

“…In semiconductors it has two components: one due to free carriers, called the plasma component, and one due to free carrier transitions across the band gap, called the interband component. The spin flip component observed by Syllaios et al [3], Yuen et al [6], Aggarwal et al [7] and others can be considered an interband component. The plasma component, θ n , is proportional to the wavelength of light used, λ, the free carrier concentration, N, and the effective mass ratio or the carriers, m*, according to [8] where q is the electron charge, B is the magnetic field strength, L is the thickness of the sample, c is the speed of light, ε o is the permittivity of free space, m o is the electron rest mass, and n is the refractive index.…”

“…A number of investigators [1][2][3] have derived a number of formulas for the electron effective mass, m*, in HgCdTe. These are all based on the band gap, Eg, which in turn, has been empirically formulated by a number of investigators [1][2][3][4].…”

“…These are all based on the band gap, Eg, which in turn, has been empirically formulated by a number of investigators [1][2][3][4]. They all result in values of m* that are within a few percent of each other.…”