First-principles study of physical properties of Zn1-xCdxTe, Zn1-xHgxTe, and Cd1-xHgxTe ternary alloys

The structural parameters, dynamic stability, electronic, and optical properties of Zn1-xCdxTe, Zn1-xHgxTe, and Cd1-xHgxTe ternary alloys are systematically studied. The dynamic stability is verified for these ternary alloys. The direct electronic transition is allowed at the Gamma point for all compounds. The band gap energy is drastically decreased from ZnTe to HgTe. The band gap can be varied in the wide range of 0-2 eV through alloy engineering. Several novel compounds show suitable band gaps (1.3-1.6 eV) and good carrier mobility for potential optoelectronic applications. The optical properties are compared in the visible region, and an improvement of the absorption coefficient is found for both Zn0.75Hg0.25Te and Cd0.75Hg0.25Te. This study will help in discovering desired materials with low toxicity and high efficiency in solar cells.

Automated summary

The structural parameters, dynamic stability, electronic, and optical properties of Zn1-xCdxTe, Zn1-xHgxTe, and Cd1-xHgxTe ternary alloys were systematically studied. These ternary alloys were found to be dynamically stable. Direct electronic transitions were allowed at the Gamma point for all compounds. The band gap energy showed a drastic decrease from ZnTe to HgTe. By alloy engineering, the band gap energy could be varied in a wide range of 0-2 eV. Several novel compounds exhibited suitable band gaps (1.3-1.6 eV) and good carrier mobility for potential optoelectronic applications. Optical properties were compared in the visible region, and an improvement in the absorption coefficient was observed for Zn0.75Hg0.25Te and Cd0.75Hg0.25Te. This study will contribute to the discovery of desired materials with low toxicity and high efficiency for solar cells.