Bifunctional OMe-PEAI Synchronizes Carrier Extraction Dynamics and Loss Mitigation toward High-Performance Perovskite Solar Cells and Modules

Abstract

Perovskite solar cells (pero-SCs) face inherent challenges due to the presence of numerous defects on the solution-processed perovskite surfaces. Conventional passivation strategies cannot address its detrimental effects on interfacial charge extraction efficiency and long-term device stability. In this study, we introduce methoxy-functionalized derivative-PEAI (OMe-PEAI) as a bifunctional interfacial mediator for the post-treatment of perovskite surfaces in n-i-p structured organic-inorganic hybrid pero-SCs. The methoxy group in OMe-PEAI, acting as a Lewis base with available lone-pair electrons, effectively interacts with uncoordinated Pb²⁺ to mitigate interfacial defects. More importantly, the strong dipole moment inherent to OMe-PEAI induces a reduction in perovskite work function, achieving optimized energy level alignment at the perovskite/Spiro-OMeTAD interface and enabling strong interfacial electronic coupling. These synergistic effects collectively enhance interfacial charge carrier extraction while suppressing non-radiative recombination losses. The optimized small-area devices (0.062 cm²) demonstrated a high-power conversion efficiency (PCE) of 25.38% with minimized voltage deficits while corresponding perovskite modules (13.93 cm²) achieved a notable PCE of 21.57%. Furthermore, OMe-PEAI-modified devices exhibited remarkable stabilities, retaining 89% and 92% of initial efficiencies after thermal stress testing (85 °C for 512 h) and maximum power point tracking (500 h), respectively.

Keywords

Defect passivation / Interfacial electronic coupling / Perovskite solar cells and modules / Stability / Energy conversion / Density functional calculations / Charge separation

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