Enhancing Hot-Electron Extraction via Naphthalene Tetracarboxylic Diimide-Based Molecule in n–i–p Perovskite Solar Cells

Extraction and utilization of hot carriers are considered viable approaches to surpass the Shockley–Queisser limit of perovskite solar cells (PSCs). Here, we introduce N,N′-bis(4-trifluoromethoxybenzyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (denoted as NDI-BOCF3) to modify the buried SnO2/perovskite interface, simultaneously accelerating hot-electron extraction and passivating interfacial defects. The NDI-BOCF3-modified SnO2 (denoted as SnO2–NDI-BOCF3) exhibits improved surface uniformity and optimized energy-level alignment and passivates oxygen vacancies (VO), thereby providing ∼22% enhancement in hot-electron extraction. Nonadiabatic molecular dynamics simulations confirmed that NDI-BOCF3 enhances hot-electron extraction via higher-frequency lattice vibrations and more ordered nonadiabatic couplings at the interface. In addition, NDI-BOCF3 passivates multisite defects across various perovskite terminations. As a result, SnO2–NDI-BOCF3 devices achieve a power conversion efficiency (PCE) of 25.06%, compared to 23.96% for a device with pristine SnO2. An increase of PCE from 8.81 to 17.50% for SnO2-free devices is also achieved. Furthermore, due to passivation, the activation barrier for positively charged iodine vacancies (VI+) increases from 0.80 to 0.87 eV, resulting in an enhancement in the thermal and photostability of the perovskite thin films.