Researchers from China's Jiangxi Science and Technology Normal University, University of Science and Technology Beijing, Xijing University and Jiangxi Normal University have developed a novel internal encapsulation strategy to enhance the environmental safety and stability of perovskite solar cells (PSCs).
Perovskite solar cells' commercialization has been hindered, according to the team, by the environmental risks associated with lead leakage. To address this pressing issue, the researchers incorporated hydroxypropyl methylcellulose phthalate (HPMCP) - a cellulose-based material with multiple adsorption modes and sites - into the perovskite layer. Acting as an internal protective film, HPMCP effectively suppresses the release of toxic lead ions (Pb²⁺) while maintaining the structural integrity of the perovskite crystals.
To evaluate the benefits of HPMCP modification, the researchers designed a series of multidimensional experiments to assess both cellular survival and plant growth in environments with potential lead exposure. Results from standardized toxicity assays were striking: cell survival rates reached over 95% after seven days of immersion in HPMCP-modified films, compared to just 2.89% in unmodified controls. Similarly, plant germination rates remained at 92.3% under HPMCP-treated conditions, closely resembling those of uncontaminated controls. These findings confirm that HPMCP not only blocks lead leakage but also minimizes its ecological impact - reducing lead absorption in plants by up to 96.8%.
Beyond environmental improvements, the modification also enhances device performance. The HPMCP-modified PSCs achieved a power conversion efficiency (PCE) of 26.27%, up from 23.43% in control devices. Stability tests further demonstrated that these modified cells retained 93% of their original efficiency after 1200 hours under conditions of 85% relative humidity - even without external encapsulation.
By integrating environmental protection with performance optimization, this work establishes a benchmark for future risk assessment and green design in perovskite solar cell research. The proposed internal encapsulation approach and ecological evaluation framework pave the way toward safer, more sustainable commercialization of high-performance PSCs.
