Multicarrier conduction and Boltzmann transport analysis of heavy hole mobility in HgCdTe near room temperature

Abstract

Magnetotransport measurements in pulsed fields up to 15 T have been performed on mercury cadmium telluride (Hg1−xCdxTe, x∼0.2) bulk as well as liquid phase epitaxially grown samples to obtain the resistivity and conductivity tensors in the temperature range 220–300 K. Mobilities and densities of various carriers participating in conduction have been extracted using both conventional multicarrier fitting (MCF) and mobility spectrum analysis. The fits to experimental data, particularly at the highest magnetic fields, were substantially improved when MCF is applied to minimize errors simultaneously on both resistivity and conductivity tensors. The semiclassical Boltzmann transport equation has been solved without using adjustable parameters by incorporating the following scattering mechanisms to fit the mobility: ionized impurity, polar and nonpolar optical phonons, acoustic deformation potential, and alloy disorder. Compared to previous estimates based on the relaxation time approximation with outscattering only, polar optical scattering and ionized impurity scattering limited mobilities are shown to be larger due to the correct incorporation of the inscattering term taking into account the overlap integrals in the valence band.

Comprehensive magnetotransport characterization of two dimensional electron gas in AlGaN/GaN high electron mobility transistor structures leading to the assessment of interface roughness

“…Murthy et al 11 The multicarrier fitting revealed the presence of a high mobility and a low mobility electron in both the samples over the entire temperature range. The density of high mobility electrons remained fairly constant at low temperatures and equalled roughly with the sum of carrier densities for two subbands estimated from SdH analysis.…”

“…R xy and R xx respectively, can separate out the contribution of different carriers in parallel conduction with a reasonable accuracy. 11 In this paper we present a comprehensive analysis of magneto-transport in two distinct GaN/AlGaN HEMT structures using multicarrier fitting and SdH Oscillations. The 2DEG characteristics, mainly τ t and τ q , so obtained are utilized to evaluate the interface roughness parameters.…”