Screening ASb₂O₆ (A = Mg, Ca, Sr, Ba, or Cd) for High-Performance Transparent Conducting Oxides

Transparent conducting oxides (TCOs) play an indispensable role in modern optoelectronic technologies. However, industry primarily relies on a limited range of n-type oxides, severely constraining the design flexibility and optimization of optoelectronic device architectures. Expanding the range of known TCOs would significantly broaden the available electron affinities, facilitating precise energetic matching and thereby enhancing device performance. Recently, Sb-(V)-based oxides have emerged as promising candidates, introducing an unexplored class of potential TCOs. In this study, we performed a computational screening of the ASb₂O₆ series (A = Mg, Ca, Sr, Ba, or Cd) to identify promising TCO candidates. Our analysis reveals that Ga-doped MgSb₂O₆ has a moderate carrier concentration of around 10¹⁷ cm^-3, which can be further enhanced with higher annealing temperatures, while Y-doped CdSb₂O₆ is predicted to be a degenerate TCO. Experimental characterization of solid-state synthesized Y-doped CdSb₂O₆ powders corroborates these computational predictions, where Y incorporation leads to a Burstein-Moss widening of the optical band gap and a 0.1 eV shift of XPS core levels to higher binding energies, confirming a Fermi-level rise due to n-type doping. In addition, the resonant nature of Y_Cd preserves high mobility and reinforces the material's strong potential for practical applications in next-generation optoelectronic devices.