Bands Structure and Magneto-Transport Properties in n Type Narrow Gap Semimetallic, Two-Dimensional and Far-Infrared Detector HgTe/CdTe Superlattice

Abstract

We report here correlations between high magnetic field magneto-transport properties and bands structure E(d2), E(kz) and E(kp), respectively, in the direction of growth and in plane of the superlattice; performed in the envelope function formalism in HgTe (d1=40 nm)/CdTe(d2=15 nm) superlattice (SL). The energy E(d2, Γ, 4.2 K), shown that when d2 increase the gap Eg decrease to zero at the transition semiconductor to semimetal conductivity behaviour (at d2=10 nm) and become negative accusing a semimetallic two-dimensional conduction. A reversal of the sign of the Hall coefficient occurs at about 3.2 T. It may be inferred to the existence of, at least, two types of carriers which suggests a semimetallic conduction. The Hall constant RH(B) lead to an electron mobility μn=6700 and n=6.2 1011 cm−2 (with μn/μp=15 and p/n=42). The formalism used here predicts that this sample is a narrow gap semimetallic, two-dimensional and far-infrared detector