Features of the band structure and conduction mechanisms of n-HfNiSn heavily doped with Y

The crystalline and electronic structures, energy, kinetic, and magnetic characteristics of n -HfNiSn semiconductor heavily doped with Y acceptor impurity are studied in the ranges: T = 80–400 K, N A Y ≈ 1.9 × 10 20 –5.7 × 10 21 cm –3 ( x = 0.01–0.30), and H ≤ 10 kG. The nature of the mechanism of structural defect generation is determined, which leads to a change in the band gap and the degree of semiconductor compensation, the essence of which is the simultaneous reduction and elimination of structural donor-type defects as a result of the displacement of ~1% of Ni atoms from the Hf (4 a ) site, and the generation of structural acceptor-type defects by substituting Hf atoms with Y atoms at the 4 a site. The results of calculations of the electronic structure of Hf 1– x Y x NiSn are in agreement with the experimental data. The discussion is performed within the Shklovskii–Efros model of a heavily doped and compensated semiconductor.