Energy-efficient sub-thermionic switching in group-V nanoribbon TFETs for beyond-CMOS logic

The scaling limits of conventional CMOS technology have intensified the search for steep-slope switching devices capable of reducing power consumption beyond the thermionic limit. Tunnel field-effect transistors (TFETs) are promising candidates for this purpose; however, simultaneously achieving sub-thermionic switching (SS < 60 mV dec⁻ 1 ) and high drive current at deeply scaled channel lengths remains a major challenge. In this work, density functional theory (DFT) combined with the non-equilibrium green’s function (NEGF) formalism is employed to investigate phosphorene, arsenene, and antimonene nanoribbon TFETs in both armchair and zigzag configurations, benchmarked against the International roadmap for devices and systems (IRDS) requirements for 10-nm logic applications. Significant performance differences are observed as a function of edge orientation and material composition. Armchair phosphorene nanoribbons (A-PNRs) exhibit excessive ambipolar leakage and fail to satisfy the low-power (LP) OFF-state criterion. In contrast, armchair antimonene nanoribbons (A-SbNRs) achieve a minimum subthreshold swing of 43.9 mV dec⁻ 1 and an I ON /I OFF ratio exceeding 10⁶ in the LP regime, owing to their favorable balance between bandgap and carrier transport properties. Zigzag nanoribbon configurations consistently fail to satisfy the complete set of IRDS performance targets. Although none of the investigated materials simultaneously meet all High-Performance (HP) requirements, A-SbNRs exhibit the most balanced overall performance. These results identify armchair antimonene nanoribbons as promising channel materials for ultra-scaled, low-power TFET technologies beyond conventional CMOS electronics.