The quest for stable and efficient perovskite solar cells (PSCs) is a central focus in renewable energy research. While PSCs offer remarkable power conversion efficiencies (PCEs), their inherent instability under ambient conditions remains a significant hurdle for widespread adoption. Factors like humidity and heat can rapidly degrade the perovskite material, leading to a loss in performance. To combat this, researchers are actively investigating various additives and interface engineering strategies. Among these, 1,4-Phenylenediamine Dihydriodide (PDAI) has emerged as a particularly promising solution, significantly contributing to enhanced stability.

PDAI functions as an interface modifier by promoting the formation of a 2D perovskite layer at the crucial interface between the perovskite absorber layer and the hole transport material. This structural modification, achieved through careful control of PDAI concentration during fabrication, leads to several benefits. Scientific studies consistently show that PDAI incorporation results in larger perovskite grains, denser grain boundaries, and a reduction in charge recombination sites. This improved film morphology directly translates to a more stable and efficient device.

The enhanced stability imparted by PDAI is evident in its performance under challenging environmental conditions. When subjected to high humidity levels (e.g., 90% RH), PSCs treated with optimal PDAI concentrations retain a significantly higher percentage of their initial PCE compared to untreated devices. Similarly, in thermal stress tests, PDAI-treated cells demonstrate superior resilience, often showing a greater recovery of PCE after thermal cycles. This robust performance is attributed to the stabilizing influence of the diammonium cations within PDAI, which help to anchor the perovskite structure and protect it from decomposition pathways.

Beyond direct stability enhancement, PDAI also contributes to the self-healing capabilities of PSCs. This means that minor degradation caused by moisture exposure can be partially reversed when the device is in a dry environment, further extending its operational lifespan. This self-healing attribute, stemming from the unique chemical properties of PDAI, adds another layer of durability to the technology.

The ability of PDAI to address the critical stability concerns of PSCs makes it a valuable tool for researchers and manufacturers aiming to bring this technology to market. By optimizing the interface and improving the intrinsic properties of the perovskite film, PDAI paves the way for more reliable and long-lasting solar energy devices. Its consistent performance improvements across various stability tests underscore its importance in the ongoing development of efficient and durable perovskite solar cells.