Abstract
The electronic properties of Te doped-ZnSb systems are investigated by first-principles calculations. We focus on the Zn64Sb64−xTex 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.
Highlights
ZnSb is one of the stable compounds used in intermediate temperatures, and has attracted a lot of interest as a thermoelectric material due to its low thermal conductivity [1,2,3]
It is found that doping a proper amount of Te resulted in a change of ZnSb conductivity type from p to n [7]
The main objective of this study is to understand the doping effect on the electronic structure of ZnSb from first principles calculations and provide insight into how to find a proper doping concentration, which makes the ZnSb exhibit special electronic properties
Summary
ZnSb is one of the stable compounds used in intermediate temperatures, and has attracted a lot of interest as a thermoelectric material due to its low thermal conductivity [1,2,3]. A thermoelectric module can generally be constructed using a unicouple of p- and n-type semiconductors. It is found that doping a proper amount of Te resulted in a change of ZnSb conductivity type from p to n [7]. Te doping in ZnSb may alter the Zn/Sb ratio of the bulk material and provide additional scattering mechanism. This doping changes the electronic structure of the material and offers opportunities for optimizing its thermoelectric performance
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