The dominant role of memory-based capacitive hysteretic currents in operation of photovoltaic perovskites. (December 2020)

• Record Type: Journal Article
• Authors: Hernández-Balaguera, Enrique; Romero, Beatriz; Arredondo, Belén; del Pozo, Gonzalo; Najafi, Mehrdad; Galagan, Yulia
• Is Part Of: Nano energy. Volume 78(2020)
• Publication Date: 2020-12
• Subjects: Perovskite solar cells -- Hysteresis -- Fractional calculus -- Impedance spectroscopy -- J−V measurements -- Constant phase element; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2020.105398
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The potential opportunities of perovskite-based technology to further advance in the photovoltaic field and implement an extensive industrial application, will mainly depend on whether some of its weaknesses, such as current density-voltage ( J − V ) hysteresis, can be overcome. In this sense, a critical aspect is the understanding and the subsequent accurate description of hysteresis in perovskite cells. Here, we present the theoretical underpinnings to interpret non-ideal transient dynamics in stepwise- JV measurements, using electrical analysis strategies and fractional calculus tools. Our model was validated with experimental measurements of CsFAPbIBr-based photovoltaic perovskites of different active layer thicknesses with persistent long-range time photocurrents. It is reported that hysteresis phenomena increase with more pronounced non-ideal capacitive effects suggesting that more trapping events limit ion motion and carrier transport. Our main interest is to provide valuable information about the memory-based slow timescale dynamics, which exhibits a significant impact on the appearance of hysteresis and, to a large extent, on the operation of the solar cell. Graphical abstract: Image 1 Highlights: Analysis and interpretation of the non-ideal capacitive behavior in J - V curves. Fractional calculus was used for the first time to gain further insight regarding hysteresis. Relation between impedance response and anomalous transient dynamics. Hysteresis depends on the fractional-order pattern and the underlying memory effects. High-efficient perovskites were studied by using the proposed method.