Mechanistic insights of the key role of methylammonium iodide in thestability of perovskite material

The possible mechanisms damaging perovskite solar cells have attracted considerableattention in the photovoltaic community۱-۳. This paper specifically answered some open problemsregarding the critical role of methylammonium iodide (MAI) in informing and stabilizingperovskite cells. Surprisingly, by using Ultraviolet–visible (UV−vis) spectra, X-ray diffractionanalysis (XRD), Field emission scanning electron microscope (FE-SEM) images, and X-rayphotoelectron spectra) XPS, we found that when the molar ratio between PbI۲: MAI precursorsolution increased from ۱:۵ to ۱:۲۵, the stability of perovskite cells dramatically increased overtime. The stability of perovskite on air without any masking in the average stoichiometry wasabout five days, while when the value of MAI precursor solution increased to ۵, the perovskitefilm was unchanged for about ۱۳ days, eventually, when the value of MAI precursor solutionenhanced to ۲۵, the film of perovskite was stayed intactfor ۲۰ days. The outstanding XRD results indicated thatthe intensity of perovskite’s Indices Miler wasIncreased significantly after ۲۴ h, and the MAI’sIndices Miler was decreased, which means that theamount of MAI was consumed to produce perovskitecells. This proposed mechanism is challenging becausepieces of evidence claim that the charging of MAIcontinuously produces the perovskite cell, whichsignificantly avoided damage to the perovskitematerial.

کلیدواژه ها:

Perovskite ، Methylammonium iodide ، Stability