To answer some of these questions and to guide future experimental studies, we perform first-principles calculations to investigate the electronic structure, n-type transport properties, and doping behavior of Y 2 Te 3 . We find that there are multiple lowlying and dispersive conduction band (CB) valleys that contribute to high CB degeneracy with the possibility of further enhancement through band convergence. Electrical transport properties obtained by solving the Boltzmann transport equations reveal that electron mobility in Y 2 Te 3 is limited by polar optical phonon scattering rather than acoustic deformation potential scattering, which is generally assumed to the dominant mechanism in TE materials. Combined with a low κ L , we predict that a maximum n-type zT of 1.0-1.2 can be achieved at an optimal electron concentration of 2 × 10 20 cm -3 . Using first-principles defect calculations, we show that the optimal electron concentration can be achieved through halogen doping under Y-rich growth conditions.