Solar cells hit 27% efficiency as researchers unlock why one material beats another
Scientists have identified the molecular mechanisms behind formamidinium perovskites' superior performance in solar cells—achieving efficiencies exceeding 27%. The findings clarify why this material outperforms older alternatives and offer a roadmap for stabilizing next-generation solar technology, critical as manufacturers race to commercialize perovskite panels at scale.
Originaltitel: Molecular-level understandings and device strategies for FAPbI<sub>3</sub>-based perovskite solar cells
<p>The composition of halide perovskite has rapidly changed from methylammonium lead triiodide (MAPbI<sub>3</sub>) to formamidinium lead triiodide (FAPbI<sub>3</sub>) to achieve high-performance solar cells with power conversion efficiencies of over 27%. FAPbI<sub>3</sub> is well known for its suitable bandgap, closer to the ideal one, and improved stability under external stress. Nevertheless, the role of FA<sup>+</sup> in determining the outstanding optoelectronic properties of FAPbI<sub>3</sub>, distinct from MAPbI<sub>3</sub>, is relatively less understood. In this review, the interaction between FA<sup>+</sup> and PbI<sub>6</sub><sup>4−</sup> octahedral frameworks is investigated in comparison with MA<sup>+</sup>, which readily affects the chemical bonding nature of the inorganic framework and thus determines the optoelectronic properties and structural stability. Closely related to the fundamental understanding of FAPbI<sub>3</sub>, the progress of FAPbI<sub>3</sub>-based perovskite solar cells is discussed from a strategic point of view to resolve their metastable character and surface defect properties to provide insights into future research directions.</p>