A hybrid functional method for screening the p-type defects in wide gap semiconductor α-LiAlTe2

Authors:
Publisher website
Google Scholar
Abstract
Transparent conducting materials (TCMs) are vital in transparent electronics. Previous investigations show that ternary telluride α-LiAlTe2 possesses a wide band gap of 3.13 eV, a smaller hole-effective mass (0.69m0) and high transmittance in the visible light region [S. Kang et al., Phys. Scr., 2024, 99, 035923]. These characteristic features imply that α-LiAlTe2 is a potential TCM. However, the research on its electrical conductivity is still lacking. In this work, we utilize a hybrid functional method (Heyd–Scuseria–Ernzerhof (HSE06)) to screen the possible binary impurity phase. Under the thermodynamic equilibrium conditions, the regions for the stable phase of α-LiAlTe2 are demarcated. The effects of the intrinsic defects and the possible p-type extrinsic defects are evaluated. We find that the intrinsic defects Liint and Alint can induce n-type conductivity. Substitution defects MgAl, CaAl, NTe, PTe and AsTe are p-type defects. Both MgAl and NTe are shallow acceptor defects with the transition energy levels ε(0/−) at 0.24 eV and 0.21 eV above the valence band maximum (VBM). Under Te-rich and Li-relatively poor conditions, the acceptor defect NTe possesses a lower formation energy of 0.35 eV, implying that defect NTe could be fabricated by using the thermodynamic equilibrium fabrication method. At room temperature, the p-type electrical conductivity exceeds 60 800 S m−1 when the hole density reaches 1020 cm−3. These results indicate that α-LiAlTe2 is a promising candidate for optoelectronic applications.
Funding Information
  • Natural Science Foundation of Hubei Province (2025AFB092)

This publication has 43 references indexed in Scilit: