Ion mobility independent large signal switching of perovskite devices

The presence of mobile ions in perovskites is well known to influence the device electrostatics leading to a wide variety of anomalous characteristics related to hysteresis, efficiency degradation, low frequency capacitance, large signal switching, etc. Accordingly, the ion mobility is understood to a have a critical influence on the associated time constants/delays. Quite contrary to this broadly accepted thought, here we suggest that the time delays associated with large signal switching could show a universal behavior dictated by electronic dipoles, rather than ionic dipoles. Due to the resultant sudden and dramatic collapse of a contact layer depletion region, large signal switching delays are independent of ion mobilities. Furthermore, our detailed numerical simulations, supported by experimental results, indicate that terminal currents show a near steady state behavior well ahead of the relaxation of ionic distributions. These results have interesting implications toward the understanding and optimization of perovskite based electronic devices, including solar cells, LEDs, resistive memories, and ferroelectric memories. Published under an exclusive license by AIP Publishing.

Automated summary

The study found that in perovskite materials, the delay of large signal switching is influenced by electronic dipoles rather than ionic dipoles, which is contrary to the widely accepted belief. Through numerical simulations and experimental results, it was found that the delay of large signal switching is independent of ion mobility, which has important implications for the understanding and optimization of perovskite electronic devices.