Seebeck and Shubnikov-de Haas Effects in a Two Dimensional p-type HgTe/CdTe Superlattice

Abstract

We report here the band structure performed in the envelope function formalism, new X‐ray diffraction, Seebeck and Shubnikov‐de Haas (SDH) effects in a two dimensional p‐type HgTe (56 A) / CdTe (30 A) superlattice. At 4.2 K, the sample exhibits p type conductivity with a Hall mobility of 8200 cm2/Vs. This allowed us to observe the SDH effect with p = 1.80×1012 cm−2. The observed SDH oscillations minima are justified by the calculated Landau levels as a function of applied magnetic field. At low temperature, the thermoelectric power α ∼T0.8 indicated a collision time τ ∼ E3/2, a Fermi energy at 12 meV and an effective masse of the degenerated heavy holes gas of m*HHl=0.308 m0. In the intrinsic regime, α ∼T−3/2 and RH T3/2 indicates a gap Eg of 190 meV in agreement with calculated Eg(Γ, 300 K) =178 meV. This sample is a medium‐infrared detector, narrow gap and two‐dimensional p‐type semiconductor.