ALD-Deposited Hydroxyl-Rich NiOx to Enhance SAM Anchoring for Stable and Efficient Perovskite Solar Cells

The interface between nickel oxide (NiOx) and self-assembled monolayers (SAMs) in perovskite solar cells (PSCs) often suffers from limited adsorption strength, poor energy-level alignment, and inadequate defect passivation, which hinder device performance and stability. To address these issues, we introduce a hybrid hole selective layer (HSL) combining atomic layer deposition (ALD)-fabricated NiOx with full-aromatic SAM molecules, creating a highly stable and efficient interface. ALD NiOx, enriched with hydroxyl groups, provides robust adsorption sites for the SAM molecule MeO-PhPACz, ensuring a strong, stable interaction. This hybrid HSL enhances energy-level alignment, hole selectivity, and defect passivation at the NiOx/perovskite interface. Devices utilizing this approach demonstrate significant performance improvements, achieving a power conversion efficiency (PCE) of 21.74%, with reduced voltage losses and minimal hysteresis. Furthermore, operational stability tests reveal enhanced durability under elevated humidity and temperature conditions. These findings highlight the potential of ALD NiOx and SAM hybrid HSL to overcome existing barriers, advancing the commercial viability of PSC technologies.