Synthesis of halide perovskite thin films from an eutectic mixture of Pb(NO3)2, acetamide, and urea for fabricating resistive random-access memory (RRAM).

Abstract

Methylammonium lead iodide (MAPbI₃) perovskite is conventionally synthesized in toxic solvents such as dimethylformamide and dimethyl sulfoxide, whose associated health and environmental risks limit large-scale and sustainable production. Building on our previous work, we further developed a synthesis route for MAPbI₃ perovskite using a deep eutectic mixture composed of lead nitrate, acetamide, and urea. The resulting perovskite thin film with its intrinsic hysteresis behavior was used to fabricate resistive random-access memory (RRAM). The structure and morphology of the perovskite films were characterized by X-ray diffraction and scanning electron microscopy, respectively, while the operation of RRAM devices was evaluated by current-voltage curve measurement. The perovskite films synthesized using the eutectic mixture exhibited improved phase conversion and greater stability than those fabricated by the conventional sequential deposition method. Electrical characterization of the RRAM devices demonstrated reliable and repeatable current-voltage behavior, with strong endurance and retention performance. Notably, the devices exhibited both analog and digital resistive switching modes, underscoring their potential for multifunctional non-volatile memory and neuromorphic computing. Overall, our findings provided a reduced-hazard solvent pathway for MAPbI₃ perovskite synthesis, replacing toxic organic solvents with a low-toxicity deep eutectic system while broadening its applicability to next-generation memory technologies with implications for future sustainable information storage solutions.