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Halide anion migration in organic–inorganic metal halide perovskites significantly influences the power conversion efficiency (PCE) and hysteresis of perovskite solar cells (PSCs). These materials are sensitive to various external stimuli such as light, heat, and electrical bias, highlighting the need for novel post‐manufacturing treatment methods alongside a deeper understanding of their mechanisms. Here, a dark electro (DE) treatment is introduced that applies a negative‐positive‐negative bias to PSC under dark conditions, which is particularly effective for formamidinium (FA) lead iodide (FAPbI3) PSCs processed with a methylammonium chloride (MACl) additive. The DE treatment, followed by light soaking, results in an average PCE increase of 2.9 ± 1.8% (from an initial 18.2 ± 2.0% to 21.1 ± 0.8% after treatment) with a notable decrease in deviation. It is discovered that residual chloride anions from MACl play a critical role in the DE treatment. The migration of halide anions under a shaking electric bias is investigated using energy‐dispersive X‐ray spectroscopy (EDX) and time‐of‐flight secondary ion mass spectroscopy (TOF‐SIMS). This study elucidates the distribution and impact of residual chloride anions, providing insights into the mechanisms underlying the DE treatment. [ABSTRACT FROM AUTHOR]

Perovskite materials have recently emerged as promising candidates as an absorber layer in solar cells. In this study, the photovoltaic performance of a formamidinium lead iodide perovskite (FAPbI3) based solar cell is assessed and improved by optimizing the thickness of the active layer using the Solar Cell Capacitance Simulator (SCAPS-1D) software. The architecture of the solar cell analyzed is a conventional planar n-i-p type composed of fluorine-doped tin oxide (FTO) as the front contact, tin oxide (SnO2) as the electron transport layer (ETL), FAPbI3 as the absorber layer, lithium bis(trifluoromethylsul-phonyl)imide (LiTFSI) doped spiro-OMeTAD as the hole transport layer (HTL), and silver (Ag) as the back contact. The simulation was carried out with and without parasitic resistances. The efficiency of the ideal device was 20.95 % when absorber thickness was between 0.68 µm and 0.78 µm and 14.45 % for the non-ideal device when the series resistance Rseries= 10 Ω·cm2 and shunt resistance Rshunt= 5000 Ω·cm2. We have found that the PCE of the original non-ideal device can be increased by 26 % through optimization of layer thickness and carrier transport.

In this paper, we studied the influence of polyvinylpyrrolidone (PVP) as a stabilization additive on optical and electrical properties of perovskite formamidinium lead iodide (FAPI) polycrystalline thin films on ZnO nanorods (ZNR). FAPI (as an active layer) was deposited from a single solution on ZNR (low temperature processed electron transport layer) using a one-step method with the inclusion of an anti-solvent. The role of PVP in the formation of the active layer was investigated by scanning electron microscopy and contact angle measurements to observe the effect on morphology, while X-ray diffraction was used as a method to study the stability of the film in an ambient environment. The effect of the PVP additive on the optical and electrical properties of the perovskite thin films was studied via photoluminescence, UV-Vis measurements, and electrical impedance spectroscopy. We have demonstrated that PVP inclusion in solution-processed perovskite FAPI thin films prevents the degradation of the film in an ambient atmosphere after aging for 2 months. The inclusion of the PVP also improves the infiltration of FAPI perovskite into ZnO nanostructures, increases electrical conductivity and radiative recombination of the photo-generated charge carriers. These results show promising information for promoting PVP stabilized FAPI perovskites for the new generation of photovoltaic devices.

In this paper, we studied the influence of polyvinylpyrrolidone (PVP) as a stabilization additive on optical and electrical properties of perovskite formamidinium lead iodide (FAPI) polycrystalline thin films on ZnO nanorods (ZNR). FAPI (as an active layer) was deposited from a single solution on ZNR (low temperature processed electron transport layer) using a one-step method with the inclusion of an anti-solvent. The role of PVP in the formation of the active layer was investigated by scanning electron microscopy and contact angle measurements to observe the effect on morphology, while X-ray diffraction was used as a method to study the stability of the film in an ambient environment. The effect of the PVP additive on the optical and electrical properties of the perovskite thin films was studied via photoluminescence, UV-Vis measurements, and electrical impedance spectroscopy. We have demonstrated that PVP inclusion in solution-processed perovskite FAPI thin films prevents the degradation of the film in an ambient atmosphere after aging for 2 months. The inclusion of the PVP also improves the infiltration of FAPI perovskite into ZnO nanostructures, increases electrical conductivity and radiative recombination of the photo-generated charge carriers. These results show promising information for promoting PVP stabilized FAPI perovskites for the new generation of photovoltaic devices. [ABSTRACT FROM AUTHOR]