Self-purification effect in CdTe:Gd crystals

• Veröffentlicht in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Datum: 2008
• ISSN: 1560-8034
• Hauptverfasser: Nikonyuk, E.S., Shlyakhovyi, V.L., Kovalets, M.O., Kuchma, M.I., Zakharuk, Z.I., Savchuk, A.I., Yuriychuk, I.M.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2008
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/118666
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Self-purification effect in CdTe:Gd crystals / E.S. Nikonyuk, V.L.Shlyakhovyi, M.O. Kovalets, M.I. Kuchma, Z.I. Zakharuk, A.I. Savchuk, I.M. Yuriychuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2008. — Т. 11, № 1. — С. 40-42. — Бібліогр.: 7 назв. — англ.

The temperature dependences (T = 80 – 420 K) of the concentration of charge
 carriers and the Hall mobility in undoped CdTe and CdTe:Gd single crystals grown by
 the Bridgman method are studied. It is found that the conductivity type of CdTe:Gd
 crystals changes with increase in the impurity concentration in the melt: n-conductivity at
 5.10¹⁷ – 3.10¹⁸ cm⁻³ and p-conductivity at 3.10¹⁸ – 10¹⁹ cm⁻³. The concentrations and
 ionization energies of A₁ (EA₁ = 0.05 eV) and A₂ (EA₂ = 0.12-0.15 eV) acceptors are
 determined from the temperature dependences of the Hall coefficient and the mobility of
 carriers. A long-term thermal treatment of gadolinium-doped p-CdTe crystals in the
 range 663 – 713 K is accompanied by the “self-purification” of the material from A₂-
 acceptors and compensating donors. The Gd impurity at C₀ > 3.10¹⁸ cm⁻³ is shown to
 bring no new electrical active centers into the CdTe lattice, by reducing, at the same time,
 the background of residual impurities. It is suggested that Te precipitates and Te inclusions
 serve as sinks for the above defects.