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First principles study on the electronic properties of Zn(64)Sb(64-x)Te(x) solid solution (x = 0, 2, 3, 4).

Zhao JH, Han EJ, Liu TM, Zeng W - Int J Mol Sci (2011)

Bottom Line: We focus on the Zn(64)Sb(64-) (x)Te(x) systems (x = 0, 2, 3, 4), which respond to the 0, 1.56at%, 2.34at% and 3.12at% of Te doping concentration.In the cases of x = 2 and 3, we find that the Te element in ZnSb introduces some bands originating from Te s and p orbits and a donor energy level in the bottom of the conduction band, which induce the n-type conductivity of ZnSb.From these findings for the electronic structure and the conductivity mechanism, we predict that Te doping amounts such as 1.56at% and 2.34at% can be considered as suitable candidates for use as donor dopant.

View Article: PubMed Central - PubMed

Affiliation: College of Materials Science and Engineering, Chongqing University, Chongqing 400030, China; E-Mails: erjing_4630@yahoo.com.cn (E.-J.H.); tmliu@cqu.edu.cn (T.-M.L.); zeng_wen1982@yaoo.com.cn (W.Z.).

ABSTRACT
The electronic properties of Te doped-ZnSb systems are investigated by first-principles calculations. We focus on the Zn(64)Sb(64-) (x)Te(x) systems (x = 0, 2, 3, 4), which respond to the 0, 1.56at%, 2.34at% and 3.12at% of Te doping concentration. We confirm that the amount of Te doping will change the conductivity type of ZnSb. In the cases of x = 2 and 3, we find that the Te element in ZnSb introduces some bands originating from Te s and p orbits and a donor energy level in the bottom of the conduction band, which induce the n-type conductivity of ZnSb. From these findings for the electronic structure and the conductivity mechanism, we predict that Te doping amounts such as 1.56at% and 2.34at% can be considered as suitable candidates for use as donor dopant.

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(a) The calculated band structure; (b) Total and partial densities of states of Zn64Sb64. The Fermi level (EF) is set as relative zero.
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f2-ijms-12-03162: (a) The calculated band structure; (b) Total and partial densities of states of Zn64Sb64. The Fermi level (EF) is set as relative zero.

Mentions: Figure 2 shows the band structure and density of states (DOS) of a Zn64Sb64 cluster. A simple glance at Figure 2a shows that the overall shapes of band structures and calculated energy band gap is 0.22 eV, which is smaller than the experimental data [19], but close to the calculated value of 0.2 eV [13,20]. The deviation from the experimental value can be attributed to the well-known drawback of DFT, but the results are also advisable for the qualitative analysis [21]. Figure 2b shows the TDOS of ZnSb and partial density of states (PDOS) of Zn and Sb atoms. One can see that the valence band (VB) can generally be divided into two regions, the lower VB within −11 eV to −5 eV and the upper valence band within −5 eV to 0. The upper VB is mainly contributed by Sb p states, and the lower VB is chiefly contributed by the Sb s states and Zn d states, the conduction band (CB) is primarily contributed by Sb s and p states. We noted that the contribution of Zn based states to the valence band is substantial, which is anticipated from the small electronegativity difference between Zn and Sb. So, the ZnSb can be considered as a polarized but covalently bonded framework structure [12].


First principles study on the electronic properties of Zn(64)Sb(64-x)Te(x) solid solution (x = 0, 2, 3, 4).

Zhao JH, Han EJ, Liu TM, Zeng W - Int J Mol Sci (2011)

(a) The calculated band structure; (b) Total and partial densities of states of Zn64Sb64. The Fermi level (EF) is set as relative zero.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3116182&req=5

f2-ijms-12-03162: (a) The calculated band structure; (b) Total and partial densities of states of Zn64Sb64. The Fermi level (EF) is set as relative zero.
Mentions: Figure 2 shows the band structure and density of states (DOS) of a Zn64Sb64 cluster. A simple glance at Figure 2a shows that the overall shapes of band structures and calculated energy band gap is 0.22 eV, which is smaller than the experimental data [19], but close to the calculated value of 0.2 eV [13,20]. The deviation from the experimental value can be attributed to the well-known drawback of DFT, but the results are also advisable for the qualitative analysis [21]. Figure 2b shows the TDOS of ZnSb and partial density of states (PDOS) of Zn and Sb atoms. One can see that the valence band (VB) can generally be divided into two regions, the lower VB within −11 eV to −5 eV and the upper valence band within −5 eV to 0. The upper VB is mainly contributed by Sb p states, and the lower VB is chiefly contributed by the Sb s states and Zn d states, the conduction band (CB) is primarily contributed by Sb s and p states. We noted that the contribution of Zn based states to the valence band is substantial, which is anticipated from the small electronegativity difference between Zn and Sb. So, the ZnSb can be considered as a polarized but covalently bonded framework structure [12].

Bottom Line: We focus on the Zn(64)Sb(64-) (x)Te(x) systems (x = 0, 2, 3, 4), which respond to the 0, 1.56at%, 2.34at% and 3.12at% of Te doping concentration.In the cases of x = 2 and 3, we find that the Te element in ZnSb introduces some bands originating from Te s and p orbits and a donor energy level in the bottom of the conduction band, which induce the n-type conductivity of ZnSb.From these findings for the electronic structure and the conductivity mechanism, we predict that Te doping amounts such as 1.56at% and 2.34at% can be considered as suitable candidates for use as donor dopant.

View Article: PubMed Central - PubMed

Affiliation: College of Materials Science and Engineering, Chongqing University, Chongqing 400030, China; E-Mails: erjing_4630@yahoo.com.cn (E.-J.H.); tmliu@cqu.edu.cn (T.-M.L.); zeng_wen1982@yaoo.com.cn (W.Z.).

ABSTRACT
The electronic properties of Te doped-ZnSb systems are investigated by first-principles calculations. We focus on the Zn(64)Sb(64-) (x)Te(x) systems (x = 0, 2, 3, 4), which respond to the 0, 1.56at%, 2.34at% and 3.12at% of Te doping concentration. We confirm that the amount of Te doping will change the conductivity type of ZnSb. In the cases of x = 2 and 3, we find that the Te element in ZnSb introduces some bands originating from Te s and p orbits and a donor energy level in the bottom of the conduction band, which induce the n-type conductivity of ZnSb. From these findings for the electronic structure and the conductivity mechanism, we predict that Te doping amounts such as 1.56at% and 2.34at% can be considered as suitable candidates for use as donor dopant.

Show MeSH