Light to Electricity as Δf Coherence Transfer — USP Field Theory (msf:45736 v2.0)

This work reformulates photovoltaic conversion as a coherence-limited Δf transfer process within USP Field Theory. Instead of treating light–matter interaction purely as energy absorption, this framework interprets photovoltaic conversion as directional closure of asymmetric Δf gradients inside a semiconductor lattice. Electrical current emerges when incident oscillatory mismatch (Δf_inc) aligns with lattice transition bandwidth (Γ) within the relaxation window (τ_rel). Version 2.0 introduces: Operational mapping of USP parameters (Γ, τ_rel, I_sat) to semiconductor observables A coherence-limited yield model η(I) Saturation intensity interpretation from heating vs coherent transfer competition Explicit experimental protocols (intensity sweep, angular scan, pulsed excitation, spectral coherence test) A resonance-ratchet geometric visualization Key prediction: At high intensity (I ≫ I_sat), absorbed power continues rising while electrical efficiency decreases due to relaxation and phonon heating dominance. Balanced angular alignment and coherence control increase directional conversion efficiency. This document connects USP Δf geometry with classical band-structure physics while remaining experimentally testable.