Application of the transition semiconductor semimetal in modulated nanostructures for communication as infrared optoelectronic device

Abstract

Abstract We report here electronic properties of a two-dimensional modulated superlattice nanostructure. Our sample, grown by MBE, had a period d=d1+d2 (90 layers) of d1=5.6 nm (HgTe)/d2=3 nm (CdTe). Calculations of the specters of energy E(d2), E(kz) and E(kp), respectively, in the direction of growth and in plane of the superlattice; were performed in the envelope function formalism. The energy E (d2, Γ, 4.2 K,), shown that for each d1/d2, when d2 increase the gap Eg decrease to zero at the transition semiconductor to semimetal conductivity behavior and become negative accusing a semimetallic conduction. At 4.2 K, the sample exhibits p type conductivity with a Hall mobility of 8200 cm2/Vs. This allowed us to observe the Shubnikov-de Haas effect with p=1.80×1012 cm−2. Using the calculated effective mass ( m HH * = 0 , 297 m 0 ) of the degenerated heavy holes gas, the Fermi energy (2D) was EF=14 meV in agreement with 12 meV of thermoelectric power α. In intrinsic regime, α∼T−3/2 and RH T3/2 indicates a gap Eg=E1−HH1=190 meV in agreement with calculated Eg (Γ, 300 K)=178 meV. The formalism used here predicts that this sample is a narrow gap, two-dimensional modulated nanostructure and medium-infrared detector.