ABSTRACT Self‐assembled monolayers (SAM) have demonstrated significant potential for enhancing the performance of perovskite solar cells (PSCs). However, their incomplete surface coverage exposes defect sites on the NiO x surface, leading to detrimental non‐radiative recombination and exacerbating the perovskite degradation. To overcome these limitations, we developed a strategy of area‐selective atomic layer deposition (AS‐ALD) that precisely deposits an ultrathin AlO x layer on exposed NiO x surfaces while preserving SAM‐covered areas. This approach effectively suppresses charge recombination by blocking direct contact between NiO x and the perovskite while leveraging the intrinsic negative fixed charges in AlO x to attract holes and repel electrons. Importantly, the SAM‐covered areas remain unaffected, ensuring unhindered carrier extraction. Additionally, the deposited AlO x reduces the deleterious Ni 4+ content, which can readily trigger perovskite decomposition, thereby significantly enhancing device performance and stability. As a result, the PCE of PSCs increased to 26.41%, with perovskite modules achieving 20.88% efficiency over a 64.68 cm 2 active area. Device stability significantly improved with ∼ 95% initial PCE retained after 1500 h dark storage (ISOS‐D‐1), ∼ 80% after 800 h at 85°C (ISOS‐D‐2), ∼ 85% after 48 thermal cycles (ISOS‐T‐1), and ∼ 90% after 1300 h continuous 1‐sun illumination (ISOS‐L‐1, MPPT).
Zhang et al. (2026) studied this question.