Impedance Spectroscopy Operating Mechanisms of Perovskite Solar Cell CS۰.۰۵ (FA / MA)۰.۹۵Pb (I / Br)۳+ CsCl

The subject of stability for a long time is one of the main challenges to perovskite solar cells (PSCs) development. Therefore, an accurate understanding of the degradation mechanisms of the device is required. In this work, we use a triple cation (A = Cs / FA / MA) with a halide mixture (X = Cl / Br / I) of APbX۳ compounds as a volume ratio change (x = FAPbI۳ / MAPbBr۳) to produce perovskite solar cells. Yields were recorded at ۱۱.۹۱ %/ ۱۲.۳% for perovskites with/without CsCl compounds, respectively. The highest efficiency is equal to ۱۲.۳%. Cells made with adsorbent layers' x = ۰.۶۳ have better stability for ۱۷۰ days, while the efficiency of cells made at x = ۰.۸۳, which was higher than other cells, ۵۷% efficient initial after ۱۷۰ days was reported. By adding the volume percentage of CsCl to the maximum efficiency sample S۱ (x = ۰.۸۳), cell stability was reported to be ۷۴% of the initial Efficiency for CsCl ۱%(S۴) after ۱۷۰ days. The EIS characteristics show that after adding CsCl(۱%), the transport resistance (R۱) decreases, and the CPE۱, dependant on the dielectric properties of the perovskite material, increases by about ۴.۹ nF. The low-frequency CPE۲ increases by about ۳۳۷ mF, whereas the interface-related resistance (R۳) shows a ۱۷۹-ohm decrease. The increase in CPE۲ could be related to ions and electrons accumulation at interfaces during adding CsCl.Also, it has seen the sample x=۰.۶۳; it has excellent stability compared to the sample S۱ despite its low efficiency, so we may be to consider the Nyquist chart as a predictor of stability.

Keywords:

Organic hybrid halide perovskite , Cs۰.۰۵ (FA / MA)۰.۹۵Pb (I / Br)۳ , Spin coating method , Cesium chloride , Perovskite solar cells , Electrochemical Impedance Spectroscopy