Synthetic Powder-Based Thin (<0.1 μm) Cs3Bi2Br9 Perovskite Films for Air-Stable and Viable Resistive Switching Memory

Here, we report on the resistive switching performance of a thin Cs3Bi2Br9 perovskite film with a thickness of <0.1 μm, enabled by synthesized Cs3Bi2Br9 powder. X-ray diffraction (XRD) confirmed that the synthesized powder was crystallized in a trigonal phase with a space group of P3̅m1. Compared to the precursor mixture of CsBr and BiBr3, the synthesized powder improved solubility in dimethyl sulfoxide (DMSO), leading to a conformal coating on an indium-doped tin oxide (ITO) substrate. The Ag/Cs3Bi2Br9/ITO devices exhibited a bipolar resistive switching behavior, where a forming step occurs at about +0.5 V prior to reliably repeated switching. As a result, an operational voltage as low as +0.44 V, endurance as high as ∼2000 cycles, and retention time of about 104 s were observed, along with a multilevel storage capability as confirmed by changing the compliance currents for the SET process. A study of the conduction mechanism with a Au electrode revealed that Ohmic conduction is dominated via ion migration such as the bromide ion in Cs3Bi2Br9. The bipolar resistive switching characteristic was maintained even after storing the devices for more than one month in ambient conditions under a relative humidity of 50%, which is beneficial for viable electronic applications.