PNNL study identifies stable lead compounds for solar cell films

Pacific Northwest National Laboratory, a US government laboratory with headquarters in Washington, has conducted a study of precursor chemistry for perovskite solar cells. Pacific Northwest National Laboratory has studied dilute methylammonium iodide and lead iodide solutions in dimethylformamide through spectroscopy and modeling. Pacific Northwest National Laboratory finds that only three lead compounds, namely Pb²⁺, PbI⁺, and PbI₂, were stable thermodynamically in those solutions. Pacific Northwest National Laboratory has established that higher-orderiodoplumbates such as PbI₄²⁻, PbI₅³⁻, and PbI₆⁴⁻ were either absent or unstable upon analysis. Pacific Northwest National Laboratory reported that PbI₃⁻ was metastable while the symmetrical geometry of PbI₄²⁻ was improbable. Pacific Northwest National Laboratory indicated that these findings better define solution chemistry and facilitate the proper construction of perovskite thin films for productive solar cell production.