Parameterization of the apparent chemical inductance of metal halide perovskite solar cells exhibiting constant-phase-element behavior

Abstract

A better characterization of the rich variety of anomalous ionic-electronic mechanisms in organic-inorganic metal halide perovskite solar cells is essential to obtain a stable and physically robust interpretation of the dynamic responses obtained. Therefore, new approaches towards light intensity-induced effects understanding are intensively searched for. Among all the mechanisms whose elucidation is locked and still under live debate, the apparent inductance phenomena stand out, which are visible not only in photovoltaic devices and optoelectronic elements, but also, for instance, in electrochemical and biological systems. Usually, the negative loops in impedance spectra are modeled through ideal elements (negative capacitance or inductance) although the results show systematic deviations (constant-phase-element behavior). In most scenarios, the influence of chemical inductance dispersion is somehow neglected, that is, ideal conditions are mimicked, omitting the practical device operation. Here we reformulate the theory that captures the slow (non-electromagnetic) inductive effects in the current-voltage curves of perovskite solar cells, deciphering the microscale behavior, consisting essentially of defects associated with deep trap states, from macroscale observations and experimental measurements. The audience is potentially huge, since many authors of multidisciplinary backgrounds are genuinely interested in adequately interpreting this behavior of general character.