Oxide Hybrid Films Research Articles

Towards wearable multifunctional cellulose nanofiber/silver nanowire/graphene oxide film: Electromagnetic protection, antibacterial, and motion monitoring

Strong electromagnetic radiation has seriously threatened human body health due to the rapid development of 5G electronic devices towards millimeter wave. The demand for wearable and antibacterial materials with high-performance electromagnetic protection is very urgent, but still lack reasonable structure design to realize multifunctional structure. Here, a wearable and antibacterial cellulose nanofiber/silver nanowire/graphene oxide (CNF-Ag NWs/GO) hybrid film with a multilayer structure is successfully fabricated by a convenient dip-coating method. Such a multilayer structure is constituted by a flexible CNF substrate, electromagnetic shielding blocks of Ag NWs and encapsulation units of GO. Benefiting from the packaging of GO sheets by the hydrogen bond interaction, a dense Ag NWs conductive network is woven. The resulting film shows extremely low sheet resistance of 0.9 Ω/sq and superior electromagnetic shielding performance of 80 dB in the millimeter wave range (26-40 GHz). Meanwhile, an excellent antibacterial property and a motion monitoring ability with high sensitivity are also acquired. The work realizes a multi-functional integration and provides new insight into the development of wearable electromagnetic protection materials.

Multifunctional electrochromic yarns for variable optical and thermal regulation

In this study, tungsten oxide and polyaniline hybrid films were deposited on the surface of stainless steel yarns by electrochemical deposition, and the electrochromic yarns with double electrochromic layer structure were formed. WO3 acts as a protective layer and binder to connect PANI nanorods, thereby improving electrochemical stability and electrochromic performance. The electrochromic yarns present five color changes in the voltage range of −0.4 V-1.1 V, the optical modulation of 59.98 %, the response time of 0.75 s, the coloration efficiency of 74.89 cm2/C, good electrochemical cycling stability (100 cycles without significant degeneration) and washing durability. At the same time, stable electrochromic behavior is still maintained in the bending state. The device based electrochromic yarns also has reversible multi-color variation, fast reaction time, and long-term stability. What's more, the device can be embroidered or woven into the fabric and designed into patterns of different colors. More color combinations can be achieved by adjusting the voltage. Finally, the fabric based on multifunction electrochromic yarns are used to study the thermal shielding performance. It can effectively block thermal radiation. These results indicate that the electrochromic yarn has promising potential for high-performance optical and thermal regulation applications. This research provides a prospective strategy for constructing multifunctional electronic devices in wearable application.

Performance Improvement and Application of Degradable Poly-l-lactide and Yttrium-Doped Zinc Oxide Hybrid Films for Energy Harvesting.

Piezoelectric nanogenerators (PENGs) are booming for energy collection and wearable energy supply as one of the next generations of green energy-harvesting devices. Balancing the output, safety, degradation, and cost is the key to solving the bottleneck of PENG application. In this regard, yttrium (Y)-doped zinc oxide (ZnO) (Y-ZnO) was synthesized and embedded into polylactide (PLLA) for developing degradable piezoelectric composite films with an enhanced energy-harvesting performance. The synthesized Y-ZnO exhibits high piezoelectric properties benefiting from the stronger polarity of the Y-O bond and regulation of oxygen vacancy concentration, which improve the output performance of the composite film with Y-ZnO and PLLA (Y-Z-PLLA). The obtained open-circuit voltage (Voc), short-circuit current (Isc), and instantaneous power density of the optimized Y-Z-PLLA PENG reach 17.52 V, 2.45 μA, and 1.76 μW/cm2, respectively. The proposed PENG also shows good degradability. In addition, practical applications of the proposed PENG were demonstrated by converting biomechanical energy, such as walking, running, and jumping, into electricity.

Improved ultraviolet photodetector performances using solution-processed nitrogen-doped carbon quantum dots/ZnO hybrid thin films

We fabricated the solution-processed photodetectors using the nitrogen-doped carbon quantum dots/zinc oxide (NCQDs/ZnO) hybrid films and characterized using ultraviolet (UV) spot-light of 365 nm at 1 mW/cm2. The NCQDs adsorbed onto the surface and/or grain boundaries of ZnO crystallites control ZnO particle size (by capping) in the NCQDs/ZnO hybrid thin films, resulting in the improved film quality and decreased the dark current in the devices. The NCQDs to ZnO [%(w/v)] ratio of 1.2 × 10−3 in the hybrid film UV photodetector exhibits the stable and reproducible photoresponses with the highest responsivity & external quantum efficiency (which are ∼3 times higher), and detectivity (∼7.5 times higher) than the pristine ZnO based photodetector, attributed to the effective transfer of photogenerated electrons from NCQDs to ZnO nanoparticles in the hybrid film. The solution-processed NCQDs/ZnO hybrid films will be very much useful to improve the UV photodetector performances for the cost-effective commercial applications.

Bismuth-magnesium-oxide-based graphene oxide hybrid film for liquid crystal device application

Hybrid films containing bismuth magnesium oxide (BiMgO) and graphene oxide (GO) are investigated in this study. Solution-processed brush coating is used to fabricate the hybrid films, with the graphene oxide weight ratios adjusted to 0, 5, and 15%. The hybrid films show more stable and higher optical transmittances than the pure BiMgO film. A directional micro/nanogroove structure is observed on the hybrid film surface, which is derived from the shear stress during the brush-coating process; this anisotropic structure is used as a uniform liquid crystal (LC) alignment layer. Uniform and homogeneous LC alignment is then demonstrated via polarized optical microscopy and pretilt angle analyses, along with perfect light-control performance. Enhanced LC polar anchoring energy and hysteresis-free characteristics are observed for the brush-coated hybrid film as the GO-doping concentration is increased. Based on this perspective, the BiMgO-based GO hybrid film achieved via brush coating has potential for applications in next-generation LC systems.

Effect of molecular and atomic layer deposition thickness in zinc oxide hybrid films on surface cracks and mechanical properties of ultra-high molecular weight polyethylene

The integration of molecular/atomic layer deposition (MLD/ALD) techniques offers a versatile platform for the fabrication of functional organic-inorganic hybrid thin-film structures. In this study, we utilized a hybrid thin-film approach comprising of a zinc oxide (ZnO) ALD layer and a diethylzinc (DEZ) + hydroquinone (HQ) MLD layer to enhance the surface quality and mechanical properties. The objective of this research was to investigate the changes in surface crack pattern and mechanical properties of the hybrid thin films by varying the composition and number of MLD/ALD layers while maintaining a fixed MLD/ALD ratio of 1:5. The hybrid films were synthesized using the [(DEZ + HQ) m + (DEZ + H2O) 5 m]n structure, where the value of mxn was fixed at 200, and the value of m was varied between 5, 10, 20, 100, and 200. The hybrid films were designated as Hm, and their surface morphology was observed by scanning electron microscopy to identify the presence of cracks. The mechanical properties of the films were evaluated by measuring the hardness and elastic modulus of an ALD-coated ultra-high molecular weight polyethylene using nano-indentation examinations, and the films' behavior in the wear environment was studied through micro-scratch testing. The results indicate that H5 and H10 hybrid films exhibited no surface cracks, while serious surface cracks were observed in H20 and H100 films. X-ray diffraction analysis showed that structural changes occurred in the hybrid films, and it was speculated that this was related to surface failure. The hardness and elastic modulus values increased with an increase in the m value and showed significant differences between hybrid films. This study demonstrated that the MLD/ALD-based hybrid thin-film approach is an effective means of enhancing surface quality and mechanical properties. The findings of this study have significant implications for the development of advanced materials and coatings for various industrial applications.

Preparation of Nanostructured Sn/Ti Oxide Hybrid Films with Terpineol/PEG-Based Nanofluids: Perovskite Solar Cell Applications.

Tin oxide (SnO2) and titanium dioxide (TiO2) are recognized as attractive energy materials applicable for lead halide perovskite solar cells (PSCs). Sintering is one of the effective strategies for improving the carrier transport of semiconductor nanomaterials. Using the alternative metal-oxide-based ETL, nanoparticles are often used in a way that they are dispersed in a precursor liquid prior to their thin-film deposition. Currently, the creation of PSCs using nanostructured Sn/Ti oxide thin-film ETL is one of the topical issues for the development of high-efficiency PSCs. Here, we demonstrate the preparation of terpineol/PEG-based fluid containing both tin and titanium compounds that can be utilized for the formation of a hybrid Sn/Ti oxide ETL on a conductive substrate (F-doped SnO2 glass substrate: FTO). We also pay attention to the structural analysis of the Sn/Ti metal oxide formation at the nanoscale using a high-resolution transmission electron microscope (HR-TEM). The variation of the nanofluid composition, i.e., the concentration of tin and titanium sources, was examined to obtain a uniform transparent thin film by spin-coating and sintering processes. The maximum power conversion efficiency was obtained for the concentration condition of [SnCl2·2H2O]/[titanium tetraisopropoxide (TTIP)] = 25:75 in the terpineol/PEG-based precursor solution. Our method for preparing the ETL nanomaterials provides useful guidance for the creation of high-performance PSCs using the sintering method.

A free-standing flexible sensor MnO2–Co/rGO-CNT for effective electrochemical hydrogen peroxide sensing and real-time cancer biomarker assaying

Research on flexible biosensors is mainly concentrated on their application in acquiring information on physical signals including temperature, pH, and so on. However, there are hardly any studies on using flexible biosensors for assaying biomolecules and biomarkers caused diseases. Herein, a free-standing flexible sensor is designed for H2O2 sensing and cancer biomarker assaying, in which reduced graphene oxide and carbon nanotubes (rGO-CNT) flexible hybrid film is first obtained through self-assembly, then MnO2 nanoflowers and Co nanospheres are anchored on rGO-CNT by electrodeposition. rGO-CNT has good flexibility and conductivity. MnO2 uniformly distributed on rGO-CNT has excellent catalytic performance towards H2O2. Co not only improve the conductivity, but also supply a second active material for H2O2 sensing. Profiting from these advantages, MnO2–Co/rGO-CNT sensor shows an expanded detection range, high sensitivity, low detection limit, excellent repeatability, reproducibility, stability and selectivity. Surprisingly, it can maintain 100% of the original signal after folding 100 times, indicating deformation stability. Moreover, it can real-time monitor H2O2 released by HepG2 cells. The strategy of introducing flexible substrate material and transition metals as well as transition metal compounds provides new insight into the design of flexible electrodes and greatly promote the development of real-time detection of cancer biomarkers.

Electrically charged magnetic skyrmions

We consider magnetic oxide/heavy metal oxide hybrid film on top of a substrate with high dielectric constant. We use the double exchange model to describe the system behavior. The interface between two oxide films produces Rashba spin-orbit interaction. The phase separation appears in such a magnetic film. Combination of the phase separation and spin-orbit coupling leads to formation of electrically charged magnetic clusters with skyrmions. We show that such clusters have both electrical and topological charges. Importantly, clusters with sizes suitable for skyrmions formation may occur only for substrate with a high dielectric constant.

Electrically controlled mRNA delivery using a polypyrrole-graphene oxide hybrid film to promote osteogenic differentiation of human mesenchymal stem cells.

Direct messenger ribonucleic acid (mRNA) delivery to target cells or tissues has revolutionized the field of biotechnology. However, the applicability of regenerative medicine is limited by the technical difficulties of various mRNA-loaded nanocarriers. Herein, we report a new conductive hybrid film that could guide osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs) via electrically controlled mRNA delivery. To find optimal electrical conductivity and mRNA-loading capacity, the polypyrrole-graphene oxide (PPy-GO) hybrid film was electropolymerized on indium tin oxide substrates. We found that the fluorescein sodium salt, a molecule partially mimicking the physical and chemical properties of mRNAs, can be effectively absorbed and released by electrical stimulation (ES). The hADMSCs cultivated on the PPy-GO hybrid film loaded with pre-osteogenic mRNAs showed the highest osteogenic differentiation under electrical stimulation. This platform can load various types of RNAs thus highly promising as a new nucleic acid delivery tool for the development of stem cell-based therapeutics.Electronic Supplementary MaterialSupplementary material (electrochemical and FT-IR analysis on the film, additional SEM, AFM and C-AFM images of the film, optical and fluorescence images of cells, and the primers used for RT-qPCR analysis) is available in the online version of this article at 10.1007/s12274-022-4613-y.

Flexible nickel cobalt metal-organic frameworks/reduced graphene oxide hybrid film for high-performance supercapacitors

Self-standing metal-organic frameworks (MOFs) with high electrical conductivity and abundant active sites are attractive in enhancing the performance of supercapacitor. Herein, the flexible two-dimension nickel cobalt metal-organic frameworks/reduced graphene oxide hybrid films (2D/2D NiCo-MOFs/rGO) have been designed and prepared for high-performance supercapacitors electrode materials via a vacuum filtration and the followed heat-treatment. Graphene oxide (GO) nanosheets serve as the conductive network to enhance the electrical conductivity of MOFs as well as a binder to bond 2D NiCo-MOFs nanosheets into a film, while 2D NiCo-MOFs nanosheets contribute the main specific capacitance of hybrid films. The as-prepared 2D/2D NiCo-MOFs/rGO hybrid film displays a high area capacitance of 4.31 F cm−2 at 1 mA cm−2, and even maintains 1.56 F cm−2 at 30 mA cm−2. Additionally, an asymmetric supercapacitor is constructed by using 2D/2D NiCo-MOFs/rGO and activated carbon films as a positive and negative electrode, respectively. It displays a high energy density of 199.4 μWh cm−2 at a power density of 801.9 μW cm−2, and an outstanding cyclic stability. This study provides a facile method to fabricate the flexible MOFs-based films for directly using as supercapacitor electrode materials.

Bicontinuous laminated structure design of polypropylene/reduced graphene oxide hybrid films for thermal management

Bicontinuous laminated structure design of polypropylene/reduced graphene oxide hybrid films for thermal management

Well‐ordered nanostructured organic/inorganic hybrid thin film construction via UV nanoimprint lithography applicable to liquid crystal systems

AbstractIn this study, a well‐ordered unidirectional nanostructure was successfully imprinted on a UV curable polymer/indium oxide hybrid film using UV nanoimprint lithography (NIL). The surface morphologies of the hybrid films were analyzed by atomic force microscopy (AFM), and the uniform nanostructure with a period of 820 nm and height of 30 nm was observed on a 6 min UV‐irradiated film by line profile from AFM. The chemical modification of the films according to UV irradiation time was analyzed by X‐ray photoelectron spectroscopy. The nanopatterned hybrid film was applied to the liquid crystal (LC) alignment layer and the polarized optical microscopy and pretilt angle analysis demonstrated the highly uniform and homogeneous LC alignment state. The unidirectional nanostructure guided the LCs orientation and the aligned surface anisotropy which induces the uniform LC alignment. The hybrid film chemical affinity was analyzed by contact angle measurement, and the increased surface energy after UV irradiation contributed to the homogeneous LC alignment. Therefore, various organic/inorganic hybrid films can be used for nanostructure construction via UV NIL, and it has a high potential for application in diverse LC systems.

Physicochemically constructed zinc oxide and UV-curable polymer hybrid films for liquid crystal system

UV-nanoimprint lithography was performed with zinc oxide (ZnO) solution and a UV-curable polymer. The UV-curing time was 2, 4, or 6 min, after which the surfaces of the films were analyzed. Atomic force microscopy of the physical characteristics of the surfaces revealed that the clearest pattern was attained on the 6 min UV-cured film. Moreover, X-ray photoelectron spectroscopy analysis confirmed that varying the UV exposure time changed the composition of atoms and bonds on the surfaces of the films. Light transmittance measurements of the patterned ZnO hybrid films show that they all exhibited sufficient transmittance. To investigate the liquid crystal (LC) orientation, LC cells were fabricated with the various films into antiparallel structures. Polarized light microscopy confirmed stable LC alignment while a stable transmittance curve based on pretilt angle measurements was observed in LC cells fabricated with hybrid films exposed to UV light for more than 4 min. The relationship between the height of the groove pattern in the film and the alignment of the LC molecules was analyzed by using Berreman's model.

α-MnO2 Nanowires and Amino-Modified Reduced Graphene Oxide Hybrid Films for Constructing the Flexible High-Performance Symmetrical Supercapacitors

Graphene or its derivates are used as an electrode material for the fabrication of supercapacitors (SCs). However, graphene or its composites readily agglomerate or stack in water, which seriously imparts SC energy efficiency. Presently, we used a new composite using [Formula: see text]-MnO2 nanowires and nitrogen-doped reduced graphene oxide ([Formula: see text]-MnO2/NRGO) for the fabrication of electrodes required in symmetric SCs. Hydrothermally synthesized [Formula: see text]-MnO2 nanowires have a smooth surface, good dispersion, and a high length-to-width ratio. The formation of stable and densely networked structures and the synergy between NRGO and [Formula: see text]-MnO2 nanowires enable the [Formula: see text]-MnO2/NRGO film electrode to show a large area-specific capacitance (386.8[Formula: see text]mF[Formula: see text]cm[Formula: see text]) at 1[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] current density; the capacity retention is 62.4% when the current density increases from 1[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] to 10[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]. The flexible and symmetrical [Formula: see text]-MnO2/NRGO SC was assembled using [Formula: see text]-MnO2/NRGO film electrodes in 1 M Na2SO4 electrolyte with a cellulose paper separator, has good capacitance retention (94%), excellent Coulombic efficiency (99%) after 3000 cycles, and high energy density (28.22[Formula: see text][Formula: see text]Wh[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]) at 0.8[Formula: see text]mW[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] power density. The [Formula: see text]-MnO2 nanowires/NRGO hybrid film flexible and symmetrical SCs are characterized by high energy storage, good cycle life and Columbic efficiency, which offer promising applications in the portable and wearable electronics industry.

High-performance humidity sensor based on graphitic carbon nitride/polyethylene oxide and construction of sensor array for non-contact humidity detection

This paper presented a novel flexible humidity sensor and sensor array based on graphitic carbon nitride/polyethylene oxide (g-C3N4/PEO) hybrid film with excellent performances. The nanostructure, morphology and composition characteristics of the g-C3N4/PEO nanomaterial were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) method. The humidity sensing performances were tested under 11–97 % RH at 20 °C and the experimental results revealed that g-C3N4/PEO humidity sensor has ultrahigh response, fast response/recovery behavior, excellent repeatability and outstanding long-term stability. The humidity sensing mechanism of g-C3N4/PEO nanomaterial was further explained through complex impedance spectroscopy (CIS) and bode diagrams. This proposed high-performance humidity sensor could be applied in practical applications such as human breath monitor under different states, finger approaching and skin moisture detection. Meanwhile, a 4 × 4 sensor array was also fabricated to monitor the approaching of fingertips and identify wet objects with specific shape demonstrating great application potential of the g-C3N4/PEO humidity sensor in non-contact systems.

Disintegrable, transparent and mechanically robust high-performance antimony tin oxide/nanocellulose/polyvinyl alcohol thermal insulation films

Polymer-based thermal insulation films are widely utilized to reduce the influence of solar radiation. However, current thermal insulation films face several challenges from poor thermal insulation performance and severe environmental pollution, which are caused by the non-disintegratability of polymer substrates. Here, cellulose nanofiber (CNF)/antimony tin oxide (ATO) hybrid films with and without polyvinyl alcohol (PVA) are presented and they can be used as window thermal barrier films and personal thermal management textiles. The hybrid films exhibit prominent thermal insulation performance, blocking 91.07% ultraviolet(UV) light, reflecting 95.19% near-infrared(NIR) light, and transmitting 44.89% visible(VIS) light. Meanwhile, the hybrid films demonstrate high thermal stability, high anti-UV aging stability, and robust mechanical properties. Moreover, the used-up hybrid films based on natural cellulose are of high disintegratability and recyclability. Our present work is anticipated to open up a new avenue for the fabrication of next-generation high-performance thermal insulation films with sustainable and environmentally friendly processes.

Strong yet tough graphene/graphene oxide hybrid films

Freestanding graphene films (GFs) have attracted extensive attention due to outstanding properties. Nevertheless, GFs show poor mechanical property because of lacking inter-laminar bonding although thermal conductivity is fascinating. Graphene oxide (GO), derivative of graphene, can act as glue to adhere different substrates depending on functional groups to boost connection between substrates. Here, we prepared GO/graphene hybrid films using GO to improve the strength by Meyer method. When GO concentration increases, the tensile strength is ever enhanced from 8 to 90 MPa, which was further increased after annealing at 1500 °C. Meanwhile, the film shows excellent fracture toughness, the toughness was improved to 0.86 MJ/m3 when GO increases to 50 wt%. After 5000 cycles, the films still demonstrate excellent fatigue property and flexibility performance. Furthermore, the hybrid films show excellent electromagnetic interference shielding effectiveness (above 60 dB at 8–12 GHz). Although the annealing temperature is as low as 1500 °C, its thermal conductivity of the hybrid film with GO loading of 50 wt% still remains 600 W m−1K−1. Our hybrid strategy provides a new way to achieve multifunctional graphene films at low annealing temperature, which is promising in flexible device application.

Fabrication of rGO/CoSx-rGO/rGO hybrid film via coassembly and sulfidation of 2D metal organic framework nanoflakes and graphene oxide as free-standing supercapacitor electrode

Porous cobalt sulfide (CoSx)/reduced graphene oxide (rGO) hybrid films has been fabricated as a flexible freestanding supercapacitor electrode via the co-assembly and sulfidation of 2D metal organic framework (MOF) nanoflakes and graphene oxide (GO). Firstly, zeolitic imidazolate-67 (ZIF-67) nanocubes were added into the aqueous solution of GO to yield a mixed dispersion of ZIF-67 and GO (ZIF-GO). It was found that the morphology of ZIF-67 changed from nanocubes to 2D nanoflakes owing to the concentration change, which favored the formation of hybrid film. Secondly, the sandwich-like GO/ZIF-GO/GO hybrid film was fabricated by the successive vacuum membrane filtration of GO, ZIF-GO, and GO solutions. Finally, the hybrid film was sulfidized via a hydrothermal process using thioacetamide as the sulfur source. This process also led to the reduction of GO to rGO. The resulting rGO/CoSx-rGO/rGO hybrid film was shown to have good electrochemical performance because it combined the good pseudocapacitor property of cobalt sulfide as well as the good conductivity and electric double layer capacitor property of rGO. In addition, an all-solid-state asymmetric supercapacitor (aSC) was assembled using rGO/CoSx-rGO/rGO hybrid film and active carbon as the positive and negative electrodes, respectively. It exhibited an energy density of 10.56 Wh kg−1 and a power density of 2250 W kg−1. Also, it retained 92.8% of initial capacitance after 10,000 cycles. The good electrochemical performance revealed that the resulting aSC has great potential in the practical application of supercapacitors.

A holistic framework towards understanding the optical and dielectric behaviors of CH3NH3PbCl3 perovskites/graphene oxide hybrid films for light absorbing active layer

In this work methylammonium trichloride CH3NH3Cl3 (MACl), methylammonium lead trichloride CH3NH3PbCl3 (MAPbCl), and graphene oxide (GO) doped methylammonium lead trichloride GO-CH3NH3PbCl3 (MAPbCl:GO) perovskite based thin film coatings deposited onto glass substrates using wet-chemical based spin coating technique at varying GO concentrations (0.025, 0.050, 0.075 ​g/ml), were investigated for their structural, compositional, optical, and dielectric characteristics. Characterizations of the coatings were carried out using XRD, SEM, FTIR, and UV–Vis spectroscopic methods. The XRD patterns and scanning electron microscope images revealed the cubic and regular constructions of MAPbCl and MAPbCl:GO with higher degree of crystallinity. FTIR studies demonstrated different vibrational modes mainly dominated by the organic salt (MACl) in both structures and a few new bonds such as CC stretching, C–H (methyl) bending, CH3–NH3 rocking were observed. Effective changes in the band-gap values were observed due to GO incorporation. A good correlation among different optical parameter such as absorption coefficient, refractive index, extinction coefficient, and dielectric function was also pragmatic. A very high value of the optical conductivity of 2.02 ​× ​1014 ​Ω/nm was shown by MAPbCl:GO (0.05 ​g/ml) perovskite composite. Hence, MAPbCl:GO coatings could be successfully used as a good light absorbing layer in perovskite solar cell (PSC) in an open-air environment and may be explored for further development to achieve a stable structure.