Hysteretic effects are investigated in perovskite solar cells in the standard FTO/TiO2/CH3NH3PbI3−xClx/spiro-OMeTAD/Au configuration. We report normal (NH) and inverted hysteresis (IH) in the J-V characteristics occurring for the same device structure, the behavior strictly depending on the pre-poling bias. NH typically appears at pre-poling biases larger than the open circuit bias, while pronounced IH occurs for negative bias pre-poling. The transition from NH to IH is marked by a intermediate mixed hysteresis behavior characterized by a crossing point in the J-V characteristics. The measured J-V characteristics are explained quantitatively by the dynamic electrical model (DEM). Furthermore, the influence of the bias scan rate on the NH/IH hysteresis is discussed based on the time evolution of the non-linear polarization. Introducing a three step measurement protocol, which includes stabilization, pre-poling and measurement, we put forward the difficulties and possible solutions for a correct PCE evaluation.
@article{arxiv.1704.03300,
title = {Normal and inverted hysteresis in perovskite solar cells},
author = {George Alexandru Nemnes and Cristina Besleaga and Viorica Stancu and Lucia Nicoleta Leonat and Lucian Pintilie and Kristinn Torfason and Marjan Ilkov and Andrei Manolescu and Ioana Pintilie},
journal= {arXiv preprint arXiv:1704.03300},
year = {2017}
}