Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy

Abstract

Despite the remarkable progress in perovskite solar cells (PSCs), their instability and rapid degradation over time still restrict their commercialization. A 2D capping layer has been proved to overcome the stability issues; however, an in-depth understanding of the complex degradation processes over a prolonged time at PSC interfaces is crucial for improving their stability. In the current work, we investigated the stability of a triple cation 3D ([(FA0.83MA0.17)Cs0.05]Pb(I0.83Br0.17)3) and 2D/3D PSC fabricated by a layer-by-layer deposition technique (PEAI-based 2D layer over triple cation 3D perovskite) using a state-of-art characterization technique: electrochemical impedance spectroscopy (EIS). A long-term stability test over 24 months was performed on the 3D and 2D/3D PSCs with an initial PCE of 18.87% and 20.21%, respectively, to suggest a more practical scenario. The current-voltage (J-V) and EIS results showed degradation in both the solar cell types; however, a slower degradation rate was observed in 2D/3D PSCs. Finally, the quantitative analysis of the key EIS parameters affected by the degradation in 3D and 2D/3D PSCs were discussed.

Zero‐Waste Scalable Blade–Spin Coating as Universal Approach for Layer‐by‐Layer Deposition of 3D/2D Perovskite Films in High‐Efficiency Perovskite Solar Modules

“…The 2D PSK overlayer creates a relatively greater splitting in the Fermi level when formed on top of the 3D PSK, taking advantage of the deeper Fermi level, forming a larger gap between the electron and hole quasi‐Fermi levels under light, which leads to the optimization of energy band alignment and reduced recombination losses. [ 49 ] In agreement with the PV results, blade coating of the 2D perovskite layer can perfectly cover all the defects of the 3D perovskite surface, resulting in a reduced amount of the recombination sites. Finally, a comparison of the LF region shows that 2D perovskite overlayer can effectively increase (one order of the magnitude) the resistance against ion migration ( R 3 ) as an important process for enhancement of the device stability.…”

“…Accordingly, CPE1 represents the geometric capacitance of the high‐frequency (HF) region which is associated with the dielectric properties of the perovskite layer and charge extraction in the PSK/HTM/Au interface. [ 48,49 ] The CPE2 is related to recombination reaction at perovskite interface in the intermediate frequency (IF) region, and the CPE3 is associated with the ionic migration in the low‐frequency (LF) region. [ 48 ] A comparison of the charge transfer resistance ( R 1 ) values of Table 2 shows that the resistivity against charge extraction in both PSCs containing 2D PSK overlayer is two order of the magnitude lower than the 3D PSC, indicating a better PSK/HTM/Au junction.…”

SnO2 Passivation and Enhanced Perovskite Charge Extraction with a Benzylamine Hydrochloric Interlayer

“…The modeling results are displayed in Table S1. Because of the small transmission resistance of the device under bias voltage, it can be considered that the composite resistance ( R cr ) of internal interfaces is dominant in the device. , Composite resistance is mainly related to interface charge accumulation. When there are a large number of defects at the interface between the perovskite layer and SnO 2 , the charge carriers accumulate there.…”

In Situ and Operando Characterizations of Metal Halide Perovskite and Solar Cells: Insights from Lab-Sized Devices to Upscaling Processes

“…A review on the use of IS as a tool to investigate HTM-free PSCs with various nanostructures and mesoporous layers has been published by Abdulrahim et al 396 The effect of illumination and applied potential on the impedance spectra of PSCs containing triple cation (FA/MA/ Cs) 3D and 2D/3D perovskites have also been investigated in recent work by Abdulrahim et al 397 The same group had performed a study of the Au/HTM/perovskite interface over 6 months, 398 and a study of up to 24 months using IS to analyze the charge transfer and recombination in 3D and 2D/3D PSCs. 399 In those works, the analyses were carried out at 0 V under dark conditions. The authors investigated aging effects under different applied potentials and illumination: analysis was performed throughout 5000 h of exposure of the PSCs to the ambient environment at room temperature (24 ± 1 °C).…”