Capacitive and Inductive Effects in Perovskite Solar Cells: The Different Roles of Ionic Current and Ionic Charge Accumulation

Accelerating the Assessment of Hysteresis in Perovskite Solar Cells

“…It is clearly seen that this last parameter decreases as the bias voltage increases, going from positive to negative values and thus inverting the transient dynamics. Importantly, the results obtained from numerical simulations displayed a good qualitative agreement with experimental data, giving a step beyond current–voltage curves and impedance spectra − in modeling the rich phenomenology of perovskites by using this family of mathematical models.…”

“…Based on the ionic–electronic properties of the perovskite semiconductors commonly manifested throughout a current–voltage curve in perovskite solar cells, we formulated a familiar dynamical model − outlined primarily from the following expression: j = C normalg normald V normald t + J rec + j normald + normald Q normals normald t where the total current flowing through the solar cell j is divided into four distinct pathways: (i) a displacement current that charges the geometrical capacitance C g of the perovskite material; conduction channels in which the current may be extracted from the contacts (ii) instantaneously via recombination processes J rec or (iii) slowly with an ion-modulated current j d ; and (iv) an interfacial current in the sense of a corresponding charge Q s . For the recombination current, note that we consider, throughout the Letter, J rec = J rec0 e qV / n rec kT , where q is the electron charge, n rec is an ideality factor, k is Boltzmann's constant, and T is the absolute temperature.…”

Electrical Charge Coupling Dominates the Hysteresis Effect of Halide Perovskite Devices

“…Many authors have proposed interpretations of the hysteresis effects and negative capacitance effects by the ionic-electronic coupling that is broadly observed in halide perovskites. − ,,− However, the detailed mechanism of the interaction that gives rise to the inductive effects has not been clarified yet. A recent paper by Nemnes and co-workers has suggested a classification of recombination effects in terms of either current or charge dominated coupling. In the following we further elaborate on such framework, to explain experimental trends observed in the literature by decisive different properties of the models.…”

Mixed Ionic‐Electronic Conduction Enables Halide‐Perovskite Electroluminescent Photodetector

“…We further denote this barrier change as $$\Phi _{\text{ion}}$$ (Figure 1c,d); it gates the electronic component of current. [ 38–40 ] Noticeably, the modulation of the Schottky barrier by mobile ions is not unique for halide‐perovskite materials: it is a general transport mechanism, studied earlier for various classes of materials with mobile ions, such as MoS 2 , TiO 2 , and HfO 2 . [ 41–43 ] In addition to ionic modulation, the photoabsorbed carriers create a similar interface modulation, which is further referred to as $$\Phi _{\text{photo}}$$ (Figure 1c,d).…”