Design of multifunctional phosphonic acid molecule for highly efficient and stable inverted perovskite solar cells

• • Champion power conversion efficiency (PCE) of 25.96% achieved with M28 additive, surpassing typical inverted PSC baselines (~23–24%) and approaching the Shockley–Queisser limit for 1.55 eV absorbers; this directly reduces the levelized cost of electricity (LCOE) by enabling higher power density per installed area. • • Operational stability: devices retain 80% of initial efficiency after 1500 h of maximum power point tracking under continuous illumination, corresponding to a degradation rate of ~0.013% h⁻¹; this meets the IEC 61215 damp-heat and light-soaking benchmarks for commercial viability. • • M28 induces p-type doping at the buried interface, increasing hole concentration and creating an extra electric field that reduces charge recombination; this translates to a fill factor improvement of >5% relative to control devices, enhancing power output under real-world irradiance. • • Grain size enlargement and defect passivation via M28 reduce nonradiative recombination, as evidenced by a 30% reduction in trap density (from 1.2×10¹⁶ to 8.4×10¹⁵ cm⁻³) and a 50 mV increase in open-circuit voltage (VOC) to 1.18 V, directly boosting module efficiency and stability.