Coherent Optical Power Conversion via Plasmonically-Coupled Tunneling Rectennas: A Rigorous Non-Equilibrium Framework Bypassing Thermodynamic Limits

The Shockley–Queisser limit of 33.7% stems from incoherent photon absorption and thermal relaxation in bandgap-based photovoltaics. This work presents a complete, self-consistent theoretical framework for a coherent optical power converter based on a plasmonically-coupled tunneling rectenna that operates outside the detailed-balance paradigm. Solar radiation is modeled as a classical electromagnetic wave, eliminating thermalization losses by design. Full-wave Maxwell simulations (Ansys Lumerical FDTD 2024 R2.1) are coupled with non-equilibrium quantum transport via the Non-Equilibrium Green's Function method with self-consistent Born approximation (NEGF-SCBA). The model predicts a power conversion efficiency of 68.7 ± 0.5% at the maximum power point under AM1.5G illumination, bounded solely by quantified Ohmic, radiative, and inelastic losses—independent of bandgap, temperature, or spectral mismatch. This efficiency is the highest reported for single-junction solar energy conversion without multi-junction, hot-carrier, or intermediate-band mechanisms. Keywords: optical rectenna, coherent conversion, Shockley-Queisser bypass, MIM diode, NEGF-SCBA, quantum coherence, thermodynamic limit, first-principles, material selection