Vanadium centers in ZnTe crystals. II. Electron paramagnetic resonance

Abstract

Four V-related electron-paramagnetic-resonance ͑EPR͒ spectra are observed in Bridgman-grown ZnTe doped with vanadium. Two of them are attributed to the charge states V Zn 3ϩ ͑A ϩ ͒ and V Zn 2ϩ ͑A 0 ͒ of the isolated V impurity. For the ionized donor, V Zn 3ϩ ͑A ϩ ͒, the spectrum reveals the typical behavior of the expected 3 A 2 (F) ground state in tetrahedral symmetry. The incorporation on a cation lattice site could be proved by the resolved superhyperfine interaction with four Te ions. The second spectrum showing triclinic symmetry and Sϭ 3 2 is interpreted as the neutral donor state V Zn 2ϩ ͑A 0 ͒. The origin of the triclinic distortion of the cubic (T d ) crystal field could be a static Jahn-Teller effect. The two additionally observed EPR spectra are attributed to nearest-neighbor V-related defect pairs. The spectrum of the first one, V Zn 2ϩ

An electron paramagnetic resonance study of vanadium-related defects in CdTe:V:Zn

“…A second possibility is that the Zn dopant is not homogenously distributed inside the crystal with Zn-rich and Zn-free alloy regions within the same crystal of some mm dimensions. The observation of a reduced linewidth of the V 2+ -X spectrum is compatible with both cases as alloying is expected to increase the linewidths and in the case of ZnTe the linewidths are reduced to ≈5 G only [15].…”

“…The V-related defects have also recently been studied by EPR and photoluminescence in the other binary compound ZnTe [15,16]. In that case four V-related paramagnetic defects have been observed under thermal equilibrium conditions: within the notation of the atomic oxidation states they were labelled the V 3+ centre in T d symmetry, a V 2+ centre in triclinic symmetry and two trigonal V 2+ -X and V 3+ -Y defects.…”

Optical and magnetic properties of transition-metal ions in tetrahedral and octahedral compounds

“…The study of TMIs in tetrahedral compounds is little. In recent years, there has been an increasing interest in the A II B VI and A III B V semiconductor materials doped with transition-metal impurities, for example, ZnTe:Cr [6], ZnS:V [7], ZnSe:V [7][8][9], ZnO:Ni [10], because of their possible important applications [11][12][13][14][15][16]. Most TMIs doped into A II B VI semiconductor materials belong to the tetrahedral structure.…”

Theoretical investigation of optical properties and band gap engineering for Zn 1−x TM x Te ( TM = Fe, Co) alloys by modified Becke–Johnson potential

“…Hence, TMs-doped ZnTe alloys depict wide range flexibility over the chemical and physical properties, for example, incorporation of V improves the photorefractive reaction. [12] The Fe 2+ -, Co 2+ -, and Ni 2+ -doped ZnTe semiconductors have been demonstrated to effectively tune the electronic and optical properties. [13,14] Similarly, Ti-, Cr-, and Mn-doped ZnTe semiconductors result in shifts of the absorption and the reflection spectra due to the dopant nature and the respective concentration.…”