Dynamic electrical behavior of halide perovskite based solar cells

TL;DR

This paper introduces a dynamic electrical model to analyze hysteresis in perovskite solar cells, accurately reproducing experimental I-V characteristics and revealing the influence of pre-poling and scan rate on hysteresis behavior.

Contribution

The paper presents a simple yet effective dynamic electrical model that captures hysteresis effects in perovskite solar cells, providing insights into polarization relaxation and pre-conditioning.

Findings

Hysteresis amplitude peaks at intermediate scan rates.

Pre-poling affects the I-V hysteresis and over-shoot phenomena.

The model aligns well with experimental data on hysteresis behavior.

Abstract

A dynamic electrical model is introduced to investigate the hysteretic effects in the I-V characteristics of perovskite based solar cells. By making a simple ansatz for the polarization relaxation, our model is able to reproduce qualitatively and quantitatively detailed features of measured I-V characteristics. Pre-poling effects are discussed, pointing out the differences between initially over- and under-polarized samples. In particular, the presence of the current over-shoot observed in the reverse characteristics is correlated with the solar cell pre-conditioning. Furthermore, the dynamic hysteresis is analyzed with respect to changing the bias scan rate, the obtained results being consistent with experimentally reported data: the hysteresis amplitude is maximum at intermediate scan rates, while at very slow and very fast ones it becomes negligible. The effects induced by different relaxation time scales are assessed. The proposed dynamic electrical model offers a comprehensive view of the solar cell operation, being a practical tool for future calibration of tentative microscopic descriptions.