Scandium resonant impurity level in PbTe

Journal Article · Mon Apr 07 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4870230· OSTI ID:22273695

Skipetrova, L. A. ^[1]; Knotko, A. V. ^[2]; Slynko, E. I.; Slynko, V. E. ^[3]

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1. Faculty of Physics, M. V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)
2. Faculty of Chemistry, M. V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)
3. Institute of Materials Science Problems, National Academy of Sciences of Ukraine, Chernovtsy 58001 (Ukraine)

We synthesize a scandium-doped PbTe single-crystal ingot and investigate the phase and the elemental composition as well as galvanomagnetic properties of Pb{sub 1-y}Sc{sub y}Te alloys in weak magnetic fields (4.2 K ≤ T ≤ 300 K, B ≤ 0.07 T) upon varying the scandium content (y ≤ 0.02). We find that all investigated samples are single-phase and n-type. The distribution of scandium impurities along the axis of the ingot is estimated to be exponential. An increase of scandium impurity content leads to a monotonous growth of the free electron concentration by four orders of magnitude (approximately from 10{sup 16} cm{sup −3} to 10{sup 20} cm{sup −3}). In heavily doped alloys (y > 0.01), the free electron concentration at the liquid-helium temperature tends to saturation, indicating the pinning of the Fermi energy by the scandium resonant impurity level located on the background of the conduction band. Using the two-band Kane and six-band Dimmock dispersion relations for IV-VI semiconductors, dependences of the Fermi energy measured from the bottom of the conduction band E{sub c} on the scandium impurity content are calculated and the energy of the resonant scandium level is estimated to be E{sub Sc} ≈ E{sub c} + 280 meV. Diagrams of electronic structure rearrangement of Pb{sub 1-y}Sc{sub y}Te alloys upon doping are proposed.

• OSTI ID: 22273695
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 13 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
CONCENTRATION RATIO
DISPERSION RELATIONS
DOPED MATERIALS
ELECTRONIC STRUCTURE
ELECTRONS
LEAD ALLOYS
LEAD TELLURIDES
MAGNETIC FIELDS
MONOCRYSTALS
SCANDIUM
SCANDIUM ALLOYS
SEMICONDUCTOR MATERIALS
TELLURIUM ALLOYS