HOS-PV 2.0: Exceeding the Shockley-Queisser Limit via Chiral-Induced Spin Selectivity, Dexter-Sensitized Singlet Fission, and Altermagnetic Carrier Extraction
Abstract
Single-junction photovoltaic devices are fundamentally constrained by the Shockley-Queisser (SQ) thermodynamic limit (η_SQ ≈ 33.7%), primarily dictated by sub-bandgap transmission losses and the ultrafast thermalization of hot photogenerated carriers. In disordered organic photovoltaics (OPV), practical efficiency is further suppressed by low carrier mobilities and severe non-radiative bimolecular (Langevin) recombination through low-lying triplet states. Here, we present the theoretical and architectural framework for HOS-PV 2.0 (Hybrid Organic-Spintronic Photovoltaics), a single-junction quantum photovoltaic architecture that resolves both thermalization and recombination bottlenecks simultaneously. The architecture integrates four synergistic mechanisms: (1) spectral down-conversion via Singlet Fission (SF) in a wide-bandgap donor (E_S1 = 2.25 eV) coupled via short-range Dexter energy transfer to a narrow-bandgap infrared (IR) non-fullerene acceptor (E_g(IR) = 1.12 eV), eliminating the open-circuit voltage (V_oc) penalty and spectral blindness of standalone SF cells; (2) in-situ spin polarization of photogenerated charge carriers directly at the bulk heterojunction (BHJ) interface via Chiral-Induced Spin Selectivity (CISS) without external magnetic fields; (3) suppression of non-radiative bimolecular recombination and the triplet drain pathway via Pauli spin blockade inside a low-atomic-number (Z = 6) carbon matrix with weak spin-orbit coupling; and (4) lossless spin-selective carrier extraction utilizing zero-stray-field altermagnetic collectors (RuO₂ or MnTe) passivated by ultrathin chiral self-assembled monolayers (c-SAMs). Analytical drift-diffusion and detailed-balance modeling demonstrates that HOS-PV 2.0 elevates the single-junction thermodynamic limit to 45.9%, yielding a projected practical power conversion efficiency (PCE) of 35.6% (J_sc = 52.3 mA/cm², V_oc = 0.81 V, FF = 84.0%) under standard AM1.5G illumination.