Achieving low-n value phases and unobstructed carrier transport toward high-performance quasi-2D perovskite solar cells and modules

Low-n value quasi-2D perovskites offer superior stability but suffer from inefficient charge transport. Here, we introduce a tyrosine (Tyr)-mediated phase regulation strategy to overcome this trade-off. By leveraging Tyr’s multifunctional active sites, we demonstrate its dual coordination with guanidinium (GA) cations and [PbI₄]²⁻ octahedra through hydrogen bonding and cation-π interactions, which selectively stabilizes low-n phases (n ≤ 3) and optimizes favorable crystallization. This interaction not only increases low-n phase content by 7-fold (from 5.67% to 36.72%) but also enhances interlayer charge coupling, yielding films with an improved carrier diffusion length exceeding 1 μm. Consequently, devices achieve 22.14% record efficiency with minimal hysteresis. Unencapsulated devices retain 96% efficiency after 2,000 h (45% ± 5% relative humidity [RH]) and 88% after 500 h (85°C). Remarkably, a 72.47 cm² module attains a certified 20.28% efficiency, demonstrating excellent scalability. This work provides a paradigm for harmonizing efficiency and stability in low-dimensional photovoltaics, advancing their commercial viability.