Inorganic Metal Halide Perovskites Research Articles

Customizing Aniline-Derived Molecular Structures to Attain beyond 22% Efficient Inorganic Perovskite Solar Cells.

The characteristics of the soft component and the ionic-electronic nature in all-inorganic CsPbI3-xBrxperovskite typically lead to a significant number of halide vacancy defects and ions migration, resulting in a reduction in both photovoltaic efficiency and stability. Herein, we present a tailored approach in which both anion-fixation and undercoordinated-Pb passivation are achieved in situ during crystallization by employing a molecule derived from aniline, specifically 2-methoxy-5-trifluoromethylaniline (MFA), to address the above challenges. The incorporation of MFA into the perovskite film results in a pronounced inhibition of ion migration, a significant reduction in trap density, an enhancement in grain size, an extension of charge carrier lifetime, and a more favorable alignment of energy levels. These advantageous characteristics contribute to achieving a champion power conversion efficiency (PCE) of 22.14% for the MFA-based CsPbI3-xBrx perovskite solar cells (PSCs), representing the highest efficiency reported thus far for this type of inorganic metal halide perovskite solar cells, to the best of our knowledge. Moreover, the resultant PSCs exhibits higher environmental stability and photostability. This strategy is anticipated to offer significant advantages for large-area fabrication, particularly in terms of simplicity.

Rational design of organic–inorganic metal halide perovskites and encapsulation via metal–organic frameworks as a stable platform with improved deep blue emission

Rational design of organic–inorganic metal halide perovskites and encapsulation via metal–organic frameworks as a stable platform with improved deep blue emission

The Prospects and Challenges for Ambi‐Polar Vacancy‐Ordered Double Perovskite Cs2SnI6 towards Realization of High Efficiency Air‐Stable Solar‐Cells

The rapid advancements in material research for lead‐free inorganic metal halide perovskites have fuelled the pathway to design environmentally‐benign solar‐cells to cater the energy requirements for future generations. The vacancy‐ordered double perovskite Cs2SnI6 with an optimum band‐gap (∽1.3 eV), high absorption coefficient (∽105 cm‐1), ambi‐polar charge carrier transport, high structural and compositional stability coupled with simple cost‐effective solution‐based synthesis techniques seems to be an excellent candidate to design air‐stable high‐efficiency solar‐cell based applications. The review focusses on the structure‐property relationship in Cs2SnI6; and its critical dependency on growth precursors, conditions and methods. The recent advancements in material and additive engineering to obtain phase‐pure uniform continuous smooth Cs2SnI6 films; and myriad methods to modulate its opto‐electronic properties are summarized. The nature, origin and type of charge‐carriers in intrinsic and doped Cs2SnI6 is extensively discussed. The application of Cs2SnI6 in dye sensitized solar‐cell (DSSC) and planar perovskite solar‐cell (PSC) configurations are critically reviewed; and its recent progress and challenges to achieve ultimate theoretical Shockley‐Queisser limit of 30‐33% is presented. The recent experimental findings on the stability and performance of Cs2SnI6‐based solar‐cells under ambient and controlled conditions would be discussed to highlight its feasibility for the design and development of air‐stable high‐efficiency solar‐cells.This article is protected by copyright. All rights reserved.

Superfluorescence in Metal Halide Perovskites

AbstractSuperfluorescence (SF) is a unique quantum optical phenomenon where an ensemble of atoms or molecules exhibit coherent emission of an intense burst of light of high directionality, with temporal coherence. SF exhibits ultrafast optical characteristics and is considerably explored in diverse inorganic and hybrid semiconductor materials at cryogenic temperatures, including inorganic and hybrid metal halide perovskites. Notably, SF is reported in different perovskites’ nanocrystal superlattices, alongside two examples in thin films, impressively achieving SF at room temperature. The density of quantum emitters, excited state characteristics, interaction strengths, and temperature all affect the SF threshold. Although significant progress is reported in the observance of SF phenomena, a full interpretation of the relationship between the factors that determine the SF threshold and the intrinsic material properties remains unclear. This review addresses the current state‐of‐the‐art observations of SF in perovskite systems, such as nanocrystal superlattices and thin films, elucidating the optical properties, ultrafast dynamics, and the proposed mechanisms for room‐temperature SF. The review concludes with a discussion on the existing challenges, unresolved questions, and future perspectives for advancing perovskite SF research

Pyrrolidinium Derivative‐Based Ionic Liquid Achieves Defect Passivation for Efficient Perovskite Solar Cells Exceeding 23%

In the rapidly developing field of photovoltaics, organic–inorganic metal halide perovskites are outstanding for their exceptional power conversion efficiencies (PCE), exceeding 26%. However, the full potential of these materials is often undermined by the prevalence of defects within their structure and at the grain surfaces, leading to significant nonradiative recombination losses. To meet this critical challenge, this study introduces a novel strategy involving a pyrrolidinium derivative and tetrafluoroborate ionic liquid, specifically 2‐pyrrolidin‐1‐ium‐1‐ethylammonium tetrafluoroborate (PyE(BF4)2), as an additive in the perovskite precursor. This approach aims to meticulously control crystallization processes and effectively passivate defects on the surface and grain boundaries of the perovskite. The formation of N─H…I− hydrogen bonds and strong ionic interactions, PyE(BF4)2 not only stabilizes the [PbI6]4− framework but also optimizes the valence band alignment with the hole transport layer. Empirical results demonstrate that perovskite solar cells modified with PyE(BF4)2 have achieved a notable PCE of 23.80% and remarkable stability exceeding 1300 h under standard testing protocols (ISOS‐V‐1). The findings emphasize the transformative potential of multifunctional ionic liquids in enhancing the performance and durability of perovskite‐based photovoltaic devices, marking a significant step forward in pursuing sustainable and efficient solar energy solutions.

Highly luminescent CsPbX3/PMMA (X=Br, I) composites with improved stability for full-color Micro-LED displays

Inorganic metal halide perovskite quantum dots (PQDs) have recently emerged as promising candidates for color conversion materials in Micro-LED displays, due to their outstanding color purity, high absorption coefficient, tunable emission wavelength. However the inferior stability and undesirable photoluminescence quantum yield (PLQY) restrict their particle applications. Herein, CsPbX3/PMMA (X = Br, I) composites with improved stability and optical performance were successfully prepared by a general and mild in-situ polymerization strategy. The ester carbonyl (CO) group in MMA formed complexes with Pb2+, leading to the in-situ thermal polymerization of polymethyl methacrylate (PMMA) under the action of the initiator. The multifunctional PMMA can efficiently passivate halogen vacancies while acting as a barrier against the degradation caused by heat, water, and oxygen. As a result, the PLQYs and stability of PMMA-coated CsPbX3 PQDs have been significantly improved. When implementing CsPbX3/PMMA/PDMS composites as color conversion layers in Micro-LEDs, they achieve an impressive color gamut of 127.23% with excellent stability. We believe our work will stimulate the exploration of perovskite/polymer composites for industrial Micro-LED applications.

Alkali-Metal-Assisted Green-Solvent Synthesis for In Situ Growth of Perovskite Nanocrystals in Porous Materials.

Inorganic metal halide perovskite CsPbX3 (X = I, Br, and Cl) nanocrystals (NCs) are rapidly developed due to their excellent photophysical properties and potential applications in lighting, lasers, and scintillators. However, the materials for growing perovskite NCs are insoluble or hydrolyzed in most green solvents, limiting their further development. Based on rational chemical analysis, an alkali-metal-assisted green-solvent synthesis method for in situ growth of CsPbBr3 NCs within SAPO-34 zeolite with bright luminescence is developed. Water is the only solvent used in the whole process. Surprisingly, by the synergistic effect of the channel structure of SAPO-34 and alkali-metal ions crystallization regulation, the CsPbBr3 NCs embedded in SAPO-34 assisted by Na+ emit bright blue light under ultraviolet illumination, with a 30nm blue shift comparing to the CsPbBr3 NCs assisted by K+. Moreover, CsPbBr3 NCs can also be grown in mesoporous SiO2 SBA-15 and zeolites including ZSM-5, AlPO-5, and SOD, indicating that the method is universal for in situ growth of luminescent perovskite NCs in porous materials. This alkali-metal-assisted green-solvent synthesis provides a new strategy for developing high-quantum-yield, tunable-emission, and stable perovskite luminescent materials.

Efficient Deep‐Blue Light‐Emitting 2D (100)‐Oriented Perovskites and Spectral Broadening by Exciton Self‐Trapping for White‐light Emissions

AbstractEfficient narrow deep‐blue and broadband emissions in layered 2D organic–inorganic hybrid metal halide perovskites (MHPs) are attracting more attention and need further study. In this work, two (100)‐oriented 2D organic‐inorganic hybrid MHPs of (TFI)2PbBr4 and (TFI)2PbCl4·H2O (TFI = 4‐(trifluoromethyl)‐1H‐imidazole) with efficient deep‐blue and bluish‐white emissions are synthesized and the photoluminescence quantum yields (PLQYs) reached up to 81.21% and 20.23%, respectively. As both intrinsic lattice distortions of two crystals with similar crystal structure are almost negligible, they have theoretical deep‐blue emissions empirically. However, the halogen substitution of chlorine (Cl) by bromine (Br) broadened the deep‐blue photoluminescence to a bluish‐white area. Here, the spectral broadening phenomenon is discussed in detail. The (TFI)2PbBr4 film shows a narrow emission with a 16 nm full width at half maximum (FWHM) peaking at 435 nm upon excitation, and an ultraviolet‐pumped light‐emitting diode (LED) prepared by bluish‐white (TFI)2PbCl4·H2O phosphor shows a color rendering index (CRI) of ≈93 and a related color temperature (CCT) of 4162K, indicating their potential applications in deep‐blue and white LEDs, respectively.

Revealing Unusual Bandgap Shifts with Temperature and Bandgap Renormalization Effect in Phase‐Stabilized Metal Halide Perovskite Thin Films

AbstractHybrid organic–inorganic metal halide perovskites are emerging materials in photovoltaics, whose bandgap is one of the most crucial parameters governing their light‐harvesting performance. This work presents the temperature and photocarrier density dependence of the bandgap in two phase‐stabilized perovskite thin films (MA0.3FA0.7PbI3 and MA0.3FA0.7Pb0.5Sn0.5I3) using photoluminescence and absorption spectroscopy. Contrasting bandgap shifts with temperature are observed between the two perovskites. Using X‐ray diffraction and in situ high‐pressure photoluminescence spectroscopy, it is shown that thermal expansion plays only a minor role in the large bandgap blueshift, which is attributed to the enhanced structural stability of the samples. The first‐principles calculations further demonstrate the significant impact of thermally induced lattice distortions on the bandgap widening. It is proposed that the anomalous trends are caused by the competition between static and dynamic distortions. Additionally, both the bandgap renormalization and band‐filling effects are directly observed for the first time in fluence‐dependent photoluminescence measurements and are employed to estimate the exciton effective mass. The results provide new insights into the basic understanding of thermal and charge‐accumulation effects on the band structure of hybrid perovskite thin films.

Preliminary exploration of the influence of N+/NHx+ ions/groups bombardment at TiO2 ETLs on performance of MAPbI3 perovskite solar cells

The service stability of organic–inorganic hybrid metal halide perovskite solar cells (PSCs) is one of most important factors, which is seriously influenced by the decomposition of perovskite layer. Especially, the decomposition of perovskite layer could deteriorate the interface between perovskite layer and TiO2 electron transport layer (ETL). In this work, TiO2 ETLs are prepared by the sputtering technique and traditional spin-coating technique. Then, TiO2 ETLs are bombarded by N+/NHx+ ions/groups. PSCs with all TiO2 ETLs are prepared and measured. The results show that after bombardment, N+/NHx+ ions/groups could chemically react with Ti/O ions at surface of TiO2 ETLs. As a result, the conduction band minimum and transfer resistance of TiO2 ETLs both deteriorate, which decrease the power conversion efficiency of PSCs seriously. While, because anatase TiO2 (001) crystal face consists of saturated O/Ti ions and displays the highest surface free energy, TiO2 ETLs with anatase (001) preferred orientation displays the optimal restraint on deterioration of power conversion efficiency caused by N+/NHx+ ions/groups bombardment. Based on above results, TiO2 ETLs with anatase (001) preferred orientation should be the optimal one for PSCs, which could improve the service stability obviously.

Investigating the Performance of Efficient and Stable Planer Perovskite Solar Cell with an Effective Inorganic Carrier Transport Layer Using SCAPS-1D Simulation

Organic–inorganic metal halide perovskite (OIMHP) has emerged as a promising material for solar cell application due to their outstanding optoelectronics properties. The perovskite-based solar cell (PSC) demonstrates a significant enhancement in efficiency of more than 20%, with a certified efficiency rating of 23.13%. Considering both the Shockley limit and bandgap, there exists a substantial potential for further efficiency improvement. However, stability remains a significant obstacle in the commercialization of these devices. Compared to organic carrier transport layers (CTLs), inorganic material such as ZnO, TiO2, SnO2, and NiOX offer the advantage of being deposited using atomic layer deposition (ALD), which in turn improves the efficiency and stability of the device. In this study, methylammonium lead iodide (MAPbI3)-based cells with inorganic CTL layers of SnO2 and NiOX are simulated using SCAPS-1D software. The cell structure configuration comprises ITO/SnO2/CH3NH3PbI3/NiOX/Back contact where SnO2 and NiOX act as ETL and HTL, respectively, while ITO is a transparent front-end electrode. Detailed investigation is carried out into the influence of various factors, including MAPbI3 layer size, the thickness of CTLs, operating temperature parasitic resistance, light intensity, bulk defects, and interfacial defects on the performance parameters. We found that the defects in layers and interface junctions greatly influence the performance parameter of the cell, which is eliminated through an ALD deposition approach. The optimum size of the MAPbI3 layer and CTL was found to be 400 nm and 50 nm, respectively. At the optimized configuration, the PSC demonstrates an efficiency of 22.13%, short circuit current (JSC) of 20.93 mA/m2, open circuit voltage (VOC) of 1.32 V, and fill factor (FF) of 70.86%.

A Halide‐Based Perovskite CsGeX3 (X = Cl, Br, and I) for Optoelectronic and Piezoelectric Applications

AbstractBy means of the study of the first principles within the framework of density functional theory, the inorganic metal halide perovskite CsGeX3 (X = Cl, Br, and I) is thoroughly investigated for its potential application in the field of green energy harvest. The structural, electronic, optical, mechanical, and piezoelectric properties have been calculated. Herein, the computed electronic properties reveal a direct bandgap semiconducting nature with electronic bandgap E = 2.01, 1.38, and 0.85 eV for X = Cl, Br, and I, respectively. Since the most prominent absorption peak falls within the vis–UV region, this implies that they are the potential candidates for photovoltaic applications. To check and verify the thermal stability, the MD simulation was performed with time steps up to 5 ps. The highest piezoelectric coefficient values are 0.731, 1.829, and 12.48 C m−2 for X = Cl, Br, and I, respectively. The higher piezoelectric responses indicate the signature of the efficient energy materials for energy harvest through electromechanical processes.

A comprehensive DFT + U investigation of electrical, optical, and structural properties of doped CsSnCl3 Perovskite: Unveiling optoelectronic potential

In the realm of advanced electrical and photovoltaic applications, inorganic metal halide perovskites (MHP) have captured attention. However, CsSnCl3, a notable member of MHPs, displays limited electro-optical potential due to its substantial bandgap and poor visible spectrum absorbance, which impedes its ability to achieve ideal optoelectronic efficiency. In this study, we used density functional theory (DFT) and the DFT + U technique to compute and investigate the structural, elastic, electrical, and optical properties of pure CsSnCl3 and its doped phases containing Ti, V, Cr, and Mn with different concentrations. Notably, this study represents the first utilization of DFT + U to simultaneously assess the band structure of both pure and doped CsSnCl3. Through meticulous alignment with experimental data and the derivation of a suitable Hubbard U correction value (6.5), our analysis reveals a refined band structure for pristine CsSnCl3. Critically, our research transcends conventional bandgap understanding, unlocking a profound connection between bandgap modulation and enhanced optoelectronic efficiency. Specifically, our systematic exploration uncovers a noteworthy enhancement in performance for various optoelectronic applications upon doping with V, Ti, Cr, and Mn, substantiating the practicality of our approach. Investigations into mechanical stability reveal that all doped samples exhibit a remarkable ductile nature, rendering them well-suited for thin-film solar cell production and other applications demanding stability and flexibility. By bridging the gap between theory and application, our study empowers researchers and industry professionals with actionable insights for selecting the most suitable doped compositions of CsSnCl3, ushering in an era of highly efficient and environmentally sustainable optoelectronic technologies.

The device simulation of MXene-added hole-transport free perovskite solar cells

Perovskite solar cells (PSCs) without hole transport layer (HTL) based on organic and inorganic metal halide perovskite have received vast consideration in recent years. For predigestion of device structure and construction process, the exclusion of the HTL is a marvelous way. By detaching the HTL part of the devices, we could reduce the cost and complexity of the structures. Currently, a novel 2D material named Ti3C2 MXene with high electron mobility, excellent metallic conductivity and functionalized surface groups applied for tuning the energy offsets has been reported to be added in the perovskite absorber layer, leading to a remarkable power conversion efficiency (PCE) improvement. In this work, the role of MXenes in controlling the work function of the involved layers to modify the band alignment towards better performance of the cells is explained. Two HTL free structures of FTO/mTiO2/cTiO2/MAPbI3/Spiro-OMeTAD/Au named as HFRC, and FTO/mTiO2+MXene/cTiO2+MXene/MXene/MAPbI3+MXene/Spiro-OMeTAD/Au named as HFMC were simulated by SCAPS-1D software to study the response of the photovoltaic devices and obtain the highest possible efficiency considering the physics behind. To the best of our knowledge, this is the first time such structures and the results of the current simulation are studied that may be used as a guideline for other practical purposes. We present a modeling procedure that optimizes the thickness of the involved layers and specifies the optimum level of the doping concentration. We also show that by optimizing the work function of the back contact, the device performance witnesses a significant improvement, proving the considerable role of the back contact in these cells. The simulated HTL-free devices illustrate attainably PCEs of about 20.32% and 21.04% for the cells without and with MXene, under AM 1.5G illumination and absorption up to 760 (nm).

Theoretical study of the structural, electronic, mechanical, and optical of transition metal (mn, co, and ni) doped FrGeI3 perovskites

Emergence of inorganic metal halide perovskites as multifunctional optoelectronic materials are due to their exceptional tunability in optoelectronic properties. This study sought to enhance the physical and mechanical properties of lead-free FrGeI3 perovskites by introducing transition metal dopants (Mn, Co, and Ni). First-principle calculations based density functional theory (DFT) have been utilized to illustrate the impact of transition-metal doping on the structural, electronic, and light-matter interaction properties of FrGeI3. The study found that transition metal doping in FrGeI3 perovskites leads to an increase in the electronic bandgap leading to semiconducting behavior after phase stability confirmation. This study provides a sound understanding of the underlying mechanisms of transition metal doping in Fr-contained halide perovskites, which could pave the way to the headway of new optoelectronic and biomedical devices based on these materials.

Stabilization of Inorganic Perovskite Solar Cells with a 2D Dion-Jacobson Passivating Layer.

Inorganic metal halide perovskites such as CsPbI3 are promising for high-performance, reproducible, and robust solar cells. However, inorganic perovskites are sensitive to humidity, which causes the transformation from the black phase to the yellow δ, non-perovskite phase. Such phase instability has been a significant challenge to long-term operational stability. Here, a surface dimensionality reduction strategy is reported, using 2-(4-aminophenyl)ethylamine cation to construct a Dion-Jacobson 2D phase that covers the surface of the 3D inorganic perovskite structure. The Dion-Jacobson layer mainly grows at the grain boundaries of the perovskite, effectively passivating surface defects and providing favourable interfacial charge transfer. The resulting inorganic perovskite films exhibit excellent humidity resistance when submerged in an aqueous solution (isopropanol:water = 4:1 v/v) and exposed to a 50% humidity air atmosphere. The Dion-Jacobson 2D/3D inorganic perovskite solar cell (PSC) achieves a power conversion efficiency (PCE) of 19.5% with a Voc of 1.197eV. It retains 83% of its initial PCE after 1260h of maximum power point tracking under 1.2 sun illumination. The work demonstrates an effective way for stabilizing efficient inorganic perovskite solar cells.

Effect of substrate inclination angle on the evaporation-induced self-assembly of CsPbBr3 thin films

Inorganic metal halide perovskites have significant interest due to their wide applications in optoelectronics. The effect of substrate immersion angle on the evaporation-induced self-assembly of Cesium lead bromide (CsPbBr3) thin films on a glass substrate is reported in this work. Colloidal CsPbBr3 nano-crystals synthesized through the Ligand Assisted Re-precipitation (LARP) method under ambient conditions are used for self-assembly. Structural, morphological, and optical properties of the self-assembled thin films are investigated using TEM, XRD, FE-SEM, AFM, Raman, UV-visible absorption, and Photoluminescence techniques. Thin films self-assembled on a substrate inclined at 90° show the best crystallinity, larger optical band gap, and minimum grain size relative to films grown with an inclination of 0° and 45°. Self-assembled thin films exhibit preferential growth along the (004) and (220) planes for a substrate inclination angle of 90°. C-axis growth was favored when the substrate was inclined at 450. The optical band gap of the self-assembled 2D material was found to increase as the substrate angle was increased from 0° to 90°. The recombination lifetime in these self-assembled CsPbBr3 thin films was found to be ∼14 ns, exhibiting a 68% reduction relative to that measured for the colloidal nanocrystals. A shelf life of over 6 months for the self-assembled thin films with no significant degradation in their structural and optical properties has been reckoned by us presently.

Investigation of a novel inorganic cubic perovskite Ca3PI3 with unique strain‐driven optical, electronic, and mechanical properties

AbstractThe remarkable structural, optical, and electronic characteristics of inorganic perovskite materials have generated significant enthusiasm within the field of solar technology. The material Ca3PI3 belongs to the same category as inorganic metal halide perovskites. This research utilized the first‐principles density functional theory (FP‐DFT) to examine how the optical and electronic characteristics of Ca3PI3 are impacted by strain. To accurately determine the band arrangement, we incorporated the relativistic spin‐orbit coupling (SOC) effect into our calculations. The planar Ca3PI3 molecule has a direct bandgap of 1.582 eV (PBE) at its Г(gamma)‐point, but while the relativistic SOC effect is included, the bandgap decreases to 1.329 eV. Under compressive strain, the bandgap of all structures decreases, whereas under tensile strain, it increases. The optical characteristics of Ca3PI3, including the dielectric function, absorption coefficient, and electron loss function, indicate its strong absorption capabilities in the visible range, driven by its band properties. Besides, the photon energy spectrum displays a red‐shift (blue‐shift) in the absorption coefficient and dielectric function with increasing amounts of compressive (tensile) strain. Therefore, the study of the strain‐induced optical and electronic characteristics of Ca3PI3 bears valuable implications for its potential use in the design of solar cells and optoelectronic devices.

Manipulating Nucleation and Crystal Growth of Inorganic Perovskite Solar Cells.

Inorganic metal halide perovskite materials as sunlight absorbers for solar cells exhibit better thermal stability than organic-inorganic hybrid counterparts. Pure cesium lead triiodide (CsPbI3), with the most suitable band gap, suffers phase instability under an ambient environment. Nucleation and crystal growth are two crucial steps in fabricating a solution-processed perovskite film. A high-quality perovskite film with good morphology makes a significant impact on the efficiency and stability of perovskite solar cells. Dimethylformamide (DMF) is a commonly used aprotic solvent. However, it is difficult to obtain a high-quality inorganic perovskite film using DMF as a single solvent due to its slow evaporation and strong coordination with Pb2+. Here, we investigate dimethylacetamide (DMAc)/DMF as a cosolvent to prompt nucleation during the spin-coating process, leading to higher nucleation density and better surface coverage. In addition, we introduce CsBr in dimethylammonium lead triiodide (DMAPbI3)/CsI precursors to slow down the crystal growth process. CsBr does not increase the film band gap but leads to a pinhole-free film with better crystallinity. Through nucleation and crystal growth engineering, the power conversion efficiency of inorganic perovskite devices is improved to 17.67%, and ambient environment stability is significantly enhanced.

Lead-free CsCu2Br3 perovskite for multilevel resistive switching memory

Organic–inorganic metal halide perovskites have recently attracted enormous interest in the field of resistive switching memories owing to their unique electrical properties. Unfortunately, two challenges, the inadequate long-term stability and the toxicity of lead, largely hinder their further practical application. Herein, a 1D all-inorganic lead-free CsCu2Br3 perovskite is proposed for resistive switching devices to resolve these issues. The CsCu2Br3-based resistive switching devices exhibit typical bipolar resistive switching behavior with low set voltage, high on/off ratio (103), stable retention properties (>2 × 104 s), and endurance (200 cycles) in air. The unencapsulated CsCu2Br3-based device still maintains resistive switching characteristics while stored in ambient environment for over 2 months. Moreover, four on-state multilevel information storage behavior has been observed by regulating the value of compliance current during set process. The resistive switching behavior is dominated by the formation and fracture of conductive filaments, which are induced by the movement of Br− ions under electrical bias. This work offers the opportunity and strategy for the design of air-stable and environment-friendly metal halide perovskite-based memory devices.