**Author details**

(14)

+5,035 ×10-4(1-2x) T (15)

For our degenerate electrons gas the Seebeck constant is described by the formula:

*<sup>α</sup>* <sup>=</sup> (*πkB*)2*<sup>T</sup>* (*<sup>s</sup>* <sup>+</sup> 1) 3*eEF*

phonons.

small in the superlattice [17].

146 Optoelectronics - Advanced Materials and Devices

The fundamental main ideas of this work are:

tice which is the key of an infrared detector.

**6. Conclusions**

where the collision time τ Es-(1/2). This permits us to estimate the Fermi energy at E<sup>F</sup> = 91 meV (in "Figure 4(a)"), with s= 2.03 corresponding to electrons diffusion by ionized impurities, in agreement with the calculated EF=88 meV in formula (13). In intrinsic regime for T>150 K, the measure of the slope of the curve RH T3/2 indicates a gap Eg = 98 meV which agree well with calculated Eg (Γ, 300 K) = E1-HH1= 105 meV. Here αT-3/2 indicates electrons scattering by

This HgTe/CdTe superlattice is a stable alternative for application in far infrared optoelec‐ tronic devices than the random alloys Hg0.99Cd0.01Te because the small composition x=0.01,

is difficult to obtain with precision while growing the ternary alloys and the transverse ef‐ fective masse in superlattice is two orders higher than in the alloy. Thus the tunnel length is



The formalism used here predicts that the system is semiconductor, for our HgTe to CdTe thickness ratio d1/d2 = 2.69, when d2 < 100 nm. In our case, d2=3.2 nm and E<sup>g</sup> (Γ, 4.2 K) = 48 meV. In spite of it, the sample exhibits the features typical for the semiconductor n-type con‐ duction mechanism. In the used temperature range, this simple is a far-infrared detector, narrow gap and two-dimensional n-type semiconductor. Note that we had observed a semi‐

metallic conduction mechanism in the quasi 2D p type HgTe/CdTe superlattice [18].

of the superlattice; were performed in the envelope function formalism.

with Eg (Γ, 300 K) =100 meV given by the empiric formula for Hg1-xCdxTe [16]

<sup>E</sup>g(x,T)= -0,302+1,93x-0,810x²+0,832x<sup>3</sup>

Abdelhakim Nafidi

Laboratory of Condensed Matter Physics and Nanomaterials for Renewable Energy Univer‐ sity Ibn-Zohr 80000 Agadir, Morocco
