Toward scalable solar cells: optimizing atmospheric-pressure spatial atomic layer deposition SnOX for enhanced perovskite crystallization and performance

Perovskite solar cells (PSCs) hold immense promise for scalable photovoltaic technology, yet challenges in manufacturing high-performance electron transport layers (ETLs) persist. Atmospheric-pressure spatial atomic layer deposition (AP-SALD) offers a scalable alternative to conventional solution-based methods, but tin oxide (SnO X ) ETLs deposited via AP-SALD (SnO X SALD ) have underperformed compared to their nanoparticle-based counterparts (SnO X NP ). This study investigates the root causes of this performance gap by analyzing the energetic, chemical, and morphological properties of SnO X SALD ETLs and their interfaces with the perovskite. We demonstrate that post-annealing at 180 °C significantly improves SnO X SALD conductivity, enhancing device photovoltaic parameters. Furthermore, it is found that the conformal nature of AP-SALD exacerbates substrate roughness, adversely affecting perovskite crystallization, unlike spin-coating, which smoothens the surface. By optimizing the ETL thickness and employing smoother fluorine-doped tin oxide (FTO) substrates, SnO X SALD -based n-i-p PSCs achieve a power conversion efficiency (PCE) exceeding 20%, matching reference SnO X NP -based PSCs. These findings provide critical insights into interfacial engineering for scalable, high-performance PSCs, advancing AP-SALD toward industrial viability. • Atmospheric-pressure spatial ALD (AP-SALD) can deposit charge-transport layers at an industrial scale. • AP-SALD SnO X has not performed well in n-i-p perovskite solar cells. • Energetic, chemical, and morphological properties of SnO X made by AP-SALD and spin coating are compared. • Conductivity, thickness, and roughness of AP-SALD SnO X are optimized. • Efficiency of n-i-p perovskite solar cells with AP-SALD SnO X improves from ∼15% to >20%.