Work

Ion migration in perovskite solar cells: Mechanisms, consequences, and suppression strategies

Year: 2026

Type: article

Abstract: Metal halide perovskite solar cells (PSCs) have quickly become a prominent photovoltaic technology, reaching power conversion efficiencies higher than 26%. However, instability continues to be a hindrance to their commercialization, with ion migration identified as a major contributing factor. This review study offers a comprehensive overview of ion migration in PSCs, connecting atomistic mechanisms to device-level performance and degradation. Ionic transport is analyzed in terms of defect chemistry, vacancy-mediated diffusion, and the soft ionic lattice of perovskites. The roles of significant mobile species, including halide ions, organic cations, and vacancies, are discussed together with important driving forces such as electric fields, thermal activation, illumination, and concentration gradients. The strong interaction between ionic and electronic processes is accentuated as a defining feature of PSC operation, which causes current-voltage hysteresis, transient performance variations, and long-term degradation. Significant attention is paid to interfacial effects, electrode reactions, phase instability, and environmentally induced degradation pathways. Experimental and computational methods that are utilized to examine ion migration are also reviewed, which shed light on multiscale transport dynamics. Lastly, strategies to reduce ion migration, including compositional engineering, defect passivation, interfacial modification, and encapsulation, are reviewed. Despite tremendous advances, controlling ionic motion remains critical because mobile defects redistribute internal electric fields, promote interfacial reactions and phase segregation, and accelerate electrode corrosion; these coupled processes directly limit efficiency retention, operational lifetime, manufacturing yield and, ultimately, the cost per unit energy delivered by perovskite modules.

Source: Next Materials

DOI: 10.1016/j.nxmate.2026.103482