The magneto-electronic and thermoelectric properties of carbon-doped BN α-graphyne are investigated using a tight-binding method combined with Green's function formalism and Kubo-Greenwood transport theory. The study focuses on the interplay between substitutional carbon-pair impurities and perpendicular external magnetic fields as dual control parameters for tailoring the electronic structure and temperature-dependent transport response. Unlike pristine carbon α-graphyne, which exhibits semimetallic behavior, pristine BN α-graphyne possesses a wide intrinsic band gap that decreases progressively with increasing carbon-pair substitution. The application of an external magnetic field further enhances the low-energy DOS spectrum by shifting Van Hove singularities toward the Fermi level and continuously modulating the band gap of BN α-graphyne. Through the Zeeman effect, field-induced semiconductor-to-metal transitions occur for doped BN-based structures at substantially lower critical fields than in the pristine counterpart. The combined effects of carbon doping and magnetic field provide precise control over the activation temperature, transport magnitude and thermoelectric performance descriptors of BN α-graphyne. Notably, under sufficiently strong magnetic fields, BN α-graphyne exhibits metallic-like behavior, with thermodynamic and thermoelectric responses surpassing those of pristine carbon α-graphyne. The Lorenz function displays clear deviations from the Wiedemann-Franz law, reflecting the nontrivial evolution from semiconducting to quasi-metallic transport regimes. These findings establish carbon-doped BN α-graphyne as a highly tunable two-dimensional platform for next-generation nanoelectronic, spintronic and thermoelectric device applications.
