Enhanced LED Performance by Ion Migration in Multiple Quantum Well Perovskite.

Here we study the effect of ion migration on the performance of perovskite light emitting diodes (PeLEDs). We compared aromatic and linear barrier molecules in Ruddlesden-Popper and Dion-Jacobson two-dimensional perovskites having multiple quantum well (MQW) structures. PeLED devices were fabricated by using the same conditions and architecture, while their electroluminescence properties and ion migration behavior were investigated. Impedance spectroscopy measurements were used to analyze the PeLEDs, which found a direct link between the barrier molecule type, the device efficiency, and ion migration. The best performing LEDs were based on the aromatic barriers, which present dominant inductive impedance, indicating an earlier onset voltage of radiative recombination. These findings present an approach of how to control radiative emission in perovskite LEDs which opens the way for further improvement in PeLEDs and memristors.