Toward Commercial-Scale Perovskite Solar Cells: The Role of ALD-SnO₂ Buffer Layers in Performance and Stability

Hybrid organic−inorganic perovskite solar cells (PSCs) have shown significant potential in photovoltaic applications due to their superior optoelectronic properties. However, the conventional electron transport layer (ETL) of C₆₀ in PSCs poses challenges such as incomplete coverage and metal diffusion, leading to reduced performance and stability. This work explores the efficacy of atomic layer deposition (ALD) of SnO₂ as an interlayer between C₆₀ and electrode to enhance the performance and stability of devices. Devices with varying SnO₂ thicknesses were fabricated, revealing that a 15 nm ALD-SnO₂ layer optimally improved the power conversion efficiency (PCE) to 23.85%, compared to the 22.86% achieved with a BCP layer. Moreover, the SnO₂-based devices exhibited superior open-circuit voltage (V_OC), short-circuit current density (J_SC), and fill factor (FF). Modules (30 × 30 cm) with ALD-SnO₂ demonstrated notable enhancements in efficiency and uniformity, suggesting the potential for scalable commercial applications. Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) analyses confirmed the improved charge extraction and reduced recombination with the SnO₂ buffer layer. This research indicates that ALD-SnO₂ is a promising interlayer candidate for PSCs, providing a pathway toward higher efficiency and stability in perovskite solar technology.