Effect of halide-mixing on the switching behaviors of organic-inorganic hybrid perovskite memory

Abstract

Mixed halide perovskite materials are actively researched for solar cells with high efficiency. Their hysteresis which originates from the movement of defects make perovskite a candidate for resistive switching memory devices. We demonstrate the resistive switching device based on mixed-halide organic-inorganic hybrid perovskite CH3NH3PbI3−xBrx (x = 0, 1, 2, 3). Solvent engineering is used to deposit the homogeneous CH3NH3PbI3−xBrx layer on the indium-tin oxide-coated glass substrates. The memory device based on CH3NH3PbI3−xBrx exhibits write endurance and long retention, which indicate reproducible and reliable memory properties. According to the increase in Br contents in CH3NH3PbI3−xBrx the set electric field required to make the device from low resistance state to high resistance state decreases. This result is in accord with the theoretical calculation of migration barriers, that is the barrier to ionic migration in perovskites is found to be lower for Br− (0.23 eV) than for I− (0.29–0.30 eV). The resistive switching may be the result of halide vacancy defects and formation of conductive filaments under electric field in the mixed perovskite layer. It is observed that enhancement in operating voltage can be achieved by controlling the halide contents in the film.

Vacuum‐Deposited Inorganic Perovskite Memory Arrays with Long‐Term Ambient Stability

“…When a positive bias is applied to the Ag TE, negatively charged Br − ions migrate toward the TE and form a thin AgBr layer near the TE . Meanwhile, the bromide vacancies are created and accumulate from TE to BE until the V Br CFs are throughout the perovskite layer, and then the memory cell is switched to LRS . When a negative voltage is applied to the BE, the Br − ions stored near the Ag electrode migrate into the CsPbBr 3 film and recombine with V Br , leading to the rupture of V Br CFs, and the memory cell is switched back to HRS.…”

Conducting Bridge Resistive Switching Behaviors in Cubic MAPbI3, Orthorhombic RbPbI3, and Their Mixtures

“…[9,16] These outstanding properties are suitable for next-generation resistive switching memories. [19][20][21] Another strategy is adopting a passivation layer on HP films, such as polymethyl methacrylate (PMMA), zinc oxide, and ethylene diamine, so as to isolate the films from the atmosphere and complement their defects. Even though conventional CBRAMs recorded over 10 6 cycles of endurance, halide perovskite based resistive switching devices exhibited around 10 3 cycles of endurance.…”

Halide Perovskites for Applications beyond Photovoltaics

“…Resistive‐switching memories (ReRAMs) demand fast operation time, large endurance, and low power voltage . A ReRAM consists of metal–insulator–metal structures and it operates according to a reversible resistive‐switching behavior between two stable resistance states, a high resistance state (HRS) and low resistance state (LRS), which form a conductive filament or bridge.…”

“…Halide perovskites with defects have been studied to enhance carrier transport properties. For example, CH 3 NH 3 PbI 3− x Br x enhances carrier mobility and decreases the recombination rate; such characteristics in memory devices lead to low power consumption because of efficient charge transport . In 2015, Yoo et al reported a resistive‐switching effect using OHPs .…”

“…Further, Br vacancies have a lower activation energy than I vacancies, which indicates that migration species can easily move in the halide perovskite films. As a result, the power consumption of the device was reduced and it exhibited an operating electric field of ≈3.44 × 10 4 V cm −1 , long retention time of over 10 4 s, and good endurance …”