Analytical Evaluation of Lead Iodide Precursor Impurities Affecting Halide Perovskite Device Performance

26 August 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Mirroring established semiconductor technologies, halide perovskite materials synthesized from higher quality reagents display improved optoelectronic performance. In this study, we performed a semiquantitative analytical characterization of five different commercial lead iodide sources to determine the identity and concentration of impurities that affect perovskite devices. It was possible to single out acetate (OAc) and potassium (K) as key species in as-received materials, both plausibly remnant from synthesis or purification. We removed these impurities through aqueous recrystallization revealing contrasting impacts on device performance: removal of OAc was beneficial but reducing K could be detrimental. This observation indicates that the highest purity lead iodide does not guarantee the highest performing perovskite material, since certain extrinsic impurities, such as KI, can improve device performance. Fundamental and applied studies will both benefit from improved purification procedures coupled with analytical studies to better understand and control the effects of individual impurities in halide perovskite materials.


halide perovskite
analytical chemistry

Supplementary materials

Supplementary Information
Detailed materials lists, device fabrication and testing, and characterization methods, performance results of two additional device composition-architectures using the commercial lead iodide reagents, 1H-NMR quantification of acetate figure, three figures with additional TOF-SIMS data.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.