Modeling hysteresis phenomena in perovskite solar cells

Alexandru Nemnes (IFIN-HH)
DFT Seminar Room
2020-02-13 12:00:00


Perovskite solar cells (PSCs) have witnessed an impressive increase in power conversion efficiency (PCE) in the past few years, to date reaching over 25% [1], being comparable with the standard silicon based technology, at much lower fabrication costs. The dynamic hysteretic effects represent an important hallmark in the J-V characteristics of perovskite solar cells (PSCs) and recently we proposed a unified picture for normal (NH) and inverted (IH) hysteresis in samples subjected to bias pre-poling [2,3,4]. Currently, there are two main types of models which explain the J-V hysteresis in perovskite solar cells: charge accumulation models and charge collection models. Starting from the basic assumption that ions migrate [5] under the influence of the internal electric field in the PSC under bias, our extended dynamic electrical model (DEM) accounts for capacitive effects related to interfacial charge accumulation and for the modulation of the charge collection efficiency. Peculiar inductive effects (negative capacitance) experimentally observed by impedance spectroscopy are discussed in terms of recombination currents.

[2] G.A. Nemnes et al., Sol. Energy Mater. Sol. Cells 159, 197 (2017).
[3] G.A. Nemnes et al., J. Phys. Chem. C 121, 11207 (2017).
[4] D.V. Anghel et al., Physica Scripta 94, 125809 (2019).
[5] C. Besleaga et al., J. Phys. Chem. Lett. 7, 5168 (2016).

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