55 results about "Thin film morphology" patented technology

The invention relates to a perovskite solar cell and a preparation method thereof. By arranging a liquid crystal layer on the surface of an electron transmission layer or a hole transmission layer, the thin film morphology of the electron transmission layer or the hole transmission layer is improved, the defect on the surface of the electron transmission layer or the hole transmission layer is passivated, the transmission of reverse current carriers is effectively blocked, the electric leakage generation is prevented, the combination probability of electrons and holes which are generated in a perovskite light absorption layer is reduced, and the photoelectric conversion efficiency and the stability of the cell are improved; and meanwhile, the liquid crystal layer is prepared by a low-temperature solution method, and the preparation method is suitably used for roll-to-roll industrial production of the perovskite photovoltaic cell, and is simple in process and low in fabrication cost.

This invention discloses a solution method for preparing ZnO nanofilms with different morphologies. The molecular beam epitaxy method has a high cost, thus is not suitable for mass production. The thermal evaporation method has a poor controllability due to high temperature requirement. The method comprises: placing electrically conductive glass containing ZnO seeds into a mixture of Zn(NO3)2 and urotropine with pH value in 2.6-10.5, growing under refluxing at 85-95 deg.C for 6 h, washing with distilled water, and drying to obtain ZnO thin films with different sizes and morphologies. Since the whole reaction process is conducted in an inorganic solution, the method has such advantages as low cost, easy operation, no pollution, and controllable ZnO thin film morphologies. The one-dimensional ZnO thin film prepared in quasi-neutral condition can be used in solar cells, photoelectrical devices, sensors and field emitters.

The invention provides an inkjet printing preparation method of a thin film. The inkjet printing preparation method is characterized in that the appearance of the thin film prepared by inkjet printing is defined by a hydrophobic coffee-ring grid, and the appearance of the thin film includes at least one of thin film pattern, thin film size, thin film thickness or thin film morphology. The specific inkjet printing preparation method comprises the steps of: a, preparing the coffee-ring grid; b, and directly spraying ink droplets into units of the coffee-ring grid, and performing drying and post-annealing to obtain the solid-state thin film, wherein the coffee-ring grid is a hydrophobic polymer coffee-ring grid or is composed of a hydrophilic polymer layer at the lower layer and a hydrophobic polymer layer at the upper layer. The inkjet printing preparation method can be used for preparing inorganic or organic material thin films, the prepared thin films are used as a gate electrode layer, a dielectric layer, an active layer or a source / drain electrode of the thin film transistor. The inkjet printing preparation method effectively controls the droplet spreading in the inkjet printing, solves the coffee-ring problem of the prepared film layer, and can be applied to the large-area preparation of the thin film transistor devices.

The invention discloses a red and green light emitting conjugated polymer. The conjugated polymer is a single-chain fluorene-based random copolymer composed of three unary compounds. The three unary compounds are 9,9-dialkyl fluorine, 2,1,3-benzthiadiazole and 4,7-bis(2'-thienyl)-2,1,3-benzthiadiazole, and the mol ratio thereof is 1-x-y:x:y, wherein, x is not less than 0.05 but not more than 0.45, and y is not less than 0.00001 but not more than 0.0005. In the conjugated polymer, light emitting units of different colors are copolymerized on a single molecular chain by covalent bonds to produce single chain multi-spectral emission. The conjugated polymer is characterized by simple synthesis and preparation and stable thin film morphology, thus achieving emission of white light with stable spectrum, which is of great significance to the application in the fields of back light sources and lighting.

The invention relates to a perovskite solar cell and a preparation method thereof. By adding an appropriate amount of polyvinyl alcohol (PVA) into a precursor liquid, the thin film morphology of a perovskite layer is improved, the service lifetime of a photo-induced carrier is prolonged, and the photoelectric conversion efficiency of the cell is effectively improved; due to the water absorption performance of the PVA, the humidity stability of the material is also substantially improved by appropriate addition, so that long-term and stable-efficiency output of the perovskite solar cell in a high humidity environment is maintained; and meanwhile, such type of a water soluble polymer material which is used is low in cost, and large-area application of the cell is facilitated.

The invention discloses a polyfluorene polymer with a main chain containing non-conjugated units and a preparation method and application of the polyfluorene polymer. The polymer is characterized in that the non-conjugated structural units are introduced into the main chain of polyfluorene so as to achieve induction to generate a beta-phase. As everyone knows, the polyfluorene polymer is one of the most promising blue-light-emitting polymers and is considerably researched due to the fact that the polyfluorene polymer is high in fluorescence quantum efficiency, relatively good in thermal stability and electrochemistry stability, easy to functionalize at carbon-9 site of fluorene, and the like, and the beta-phase has far-reaching influence on thin film morphology, carrier transporting and device performance.

The invention discloses a strongly coupled gold nano superlattice structure and a self-assembly preparation method thereof. The superlattice structure is composed of a series of densely arranged icosidodecahedron gold nanoparticles, the average spacing between the particles is controlled from dozens of nanometers to several nanometers, the whole superlattice presents a monolayer film form, and twocharacterized plasma coupled formants exist in a visible-near infrared band range. The self-assembly preparation method combines the common effect of electrostatic and capillary adsorption. The reagents and instrument equipment selected by the invention are simple and easily available, and the self-assembly way is flexible and efficient. The prepared strongly coupled gold nano superlattice structure has an actual area up to cm<2> level, and has good repeatability. The strongly coupled gold nano superlattice structure and the preparation method provided by the invention lay the experimental foundation for constructing and designing functional novel optical materials and devices, and have important reference value for preparation of large-area superlattice by self-assembly of other form nanocrystalline structural units and application thereof.

The invention discloses a blue-light perovskite light-emitting diode and a preparation method thereof. The structure of the blue-light perovskite light-emitting diode sequentially comprises a substrate, an anode, a hole transport layer, a light-emitting layer, a passivation layer, an electron transport layer, an electron injection layer and a cathode from bottom to top, wherein the light-emitting layer is a perovskite thin film prepared from a perovskite precursor solution; when the blue-light perovskite light-emitting diode is prepared, a perovskite thin film is prepared through a perovskite precursor solution added with a thiocyanate additive, so that the thin film morphology of a light-emitting layer is adjusted through the thiocyanate additive; and after the perovskite thin film is prepared, the perovskite thin film is subjected to passivation treatment, so that the performance of the perovskite thin film is improved. The perovskite thin film is prepared based on the additive engineering of the perovskite precursor solution added with the thiocyanate additive, and the surface passivation treatment is utilized, so that the surface defects of the thin film are further reduced, and the light-emitting performance of the blue-light perovskite light-emitting diode is improved.

The invention relates to a method for preparing a crystal homogeneous type perovskite thin film, and belongs to the technical field of preparation of solar energy materials. According to the invention, the sensitizing dye-adsorbed zeolite is doped into an electrolytic sol, and thanks to the high sensitizing dye loaded in pores of the zeolite, the problems of high charge recombination rate, poor electrical contact and low conductivity in an electrolyte material is effectively modified; and meanwhile, the electrolyte is spin-coated as a base layer, so that the lead halide can be penetrated as much as possible into a mesoporous layer to become a perovskite film electron transport layer, the perovskite film is enabled to have uniform crystallite size distribution and a smooth surface, the light absorption capability of the thin film is enhanced, the charge transport capacity is enhanced, charges in the perovskite thin film are allowed to be effectively transported, the interfacial recombination is inhibited, the charge loss is reduced, the effective control of the perovskite crystallization and thin film morphology is achieved, the solar cell use efficiency is increased, and a wide range of use prospect is gained.

The invention discloses a bipolar small molecular light-emitting material based on an aromatic heterocyclo-2-S,S-dioxydibenzothiophene unit, and a preparation method and application thereof. The preparation method comprises the following step: performing Suzuki coupling reaction on an aromatic heterocyclo-2-S,S-dioxydibenzothiophene monomer and a borate monomer containing an Ar structure to obtain the bipolar small molecular light-emitting material based on an aromatic heterocyclo-2-S,S-dioxydibenzothiophene unit. The bipolar small molecular light-emitting material disclosed by the invention has solubility, film forming property and film morphology stability, also has favorable electron and hole transmission performance, and can balance carrier injection and transmission to realize effective compounding of more excitons; a light-emitting layer based on the material can avoid the phenomenon of mixing with a hole / electron transmission layer interface, thereby improving the light-emitting efficiency of a device; and the light-emitting layer based on the material dose not need to be subjected to annealing treatment during preparation of the electroluminescent device, thereby ensuring that the preparation process is simple.

The invention discloses a neutral cathode buffer layer molecular type material based on N-heterocycle groups. An aromatic ring containing alkyl chains is used as the core of the neutral cathode buffer layer molecular type material, and the N-heterocycle groups which can interact with electrodes are led into the two ends of the neutral cathode buffer layer molecular type material so as to modify the electrodes. The neutral cathode buffer layer molecular type material based on the N-heterocycle groups, disclosed by the invention, has relatively good solution processing property, good thin film morphology stability and good interface modification characteristic, is simple and convenient in synthesis and purification and improves contact characteristics between a cathode buffer layer and an active layer; and the neutral cathode buffer layer molecular type material based on the N-heterocycle groups is capable of effectively assisting metals or metal oxides such as aluminium, silver, gold and ITO (indium tin oxide) to collect electrons, avoids usage of low work function metal electrodes unstable in air and improves stability of devices.

The present invention provides a pre-drying apparatus, a film layer preparing method, a luminescent device and a preparation method thereof. The pre-drying apparatus comprises a box and an object bearing stage arranged inside the box. The box is provided with an accommodation space for disposing a solvent material, and a box door, an air inlet and an air outlet are disposed on the box. A vertical distance between the air inlet and the bottom of the box is smaller than a vertical distance between an upper surface of the object bearing stage and the bottom of the box. A sub-pixel area provided with ink is disposed on the object bearing stage, and a solvent material of a same solvent type in the ink is disposed on the bottom of the box in the pre-drying apparatus. When a liquid level of the solvent material is lower than the upper surface of the object bearing stage and is higher than the air inlet, gas entering the box from the air inlet can enable ink in the sub-pixel area uniformly flow from a middle area of the sub-pixel area and spread over the entire sub-pixel area, thereby effectively avoiding a problem of uneven thin film morphology after drying, and improving device luminous quality.

The invention relates to a viscous incompressible fluid simulation method based on SPH. The method is a high-precision and high-robustness SPH-based viscous incompressible fluid simulation method, non-physical conflicts and drift errors generated in the solving process of the method are avoided through a unified solution scheme of incompressible constraints and viscous constraints, and the problemof surface particle missing is quickly and efficiently solved in a mode of not arranging Ghost particles. Newtonian fluid with different viscosity coefficient values and non-Newtonian fluid with variable viscosity coefficients can be stably simulated, the surface form of the viscous fluid can be kept for a long time, and multiple fine movement processes such as the stretching and thinning process, the rope coiling effect and the film form of the viscous fluid can be accurately simulated.

The invention discloses a precursor solution of a copper-zinc-tin-sulfur thin film solar cell as well as a preparation method and application thereof. The invention discloses two types of simple metalcomplexes capable of preparing a high-quality precursor solution. By utilizing the metal complexes as precursor compounds, the prepared precursor solution is good in stability and can be used for preparing a copper-zinc-tin-sulfur thin film light absorption material which is high in crystallization quality, good in thin film morphology and free of an impurity phase, and a copper-zinc-tin-sulfur thin film solar cell prepared from the copper-zinc-tin-sulfur thin film light absorption material is high in photoelectric conversion efficiency. By using the metal complexes, the preparation process of the precursor solution is simplified, the quality of the precursor solution is improved, the energy conversion efficiency of a photovoltaic device is improved, and the precursor solution has a greatindustrial application potential.

The invention discloses a synthetic method of N, N-diaryl-2-bromine-6-naphthylamine. The synthetic method comprises the step of carrying out C-N coupled reaction on halogenated arene and a 6-bromine-2-naphthylamine unit to obtain an N, N-diaryl-2-bromine-6-naphthylamine unit. The invention also discloses application of N, N-diaryl-2-bromine-6-naphthylamine, namely, N, N-diaryl-2-bromine-6-naphthylamine provided by the invention is adopted as the raw material to prepare an organic semiconductor material; compared with the conventional synthetic method, the synthetic method of N, N-diaryl-2-bromine-6-naphthylamine provided by the invention is simple in synthetic route and high in comprehensive yield; the organic semiconductor material which contains a diaryl naphthyl amine functional unit and is prepared from N, N-diaryl-2-bromine-6-naphthylamine provided by the invention is relatively high in hole mobility and thin film morphology stability.

The invention relates to a method of preparing a hole injection layer in an organic light emitting diode based on a collosol-gel method, and a constructed organic light emitting diode, and belongs tothe technical field of basic electrical elements. The method mainly comprises the two technical links of preparation of VOx precursor liquid and preparation of the hole injection layer. Equipment usedin the method is simple; a synthesis technology is simple; the method is easy to operate and good in repeatability; and the VOx precursor liquid prepared in the method has the advantages of water solubility, wide concentration tolerance, stability, excellent film morphology and the like and can be used for constructing the high-performance visible light or ultraviolet organic light emitting diode.

The invention discloses a hot filament chemical vapor thin film deposition growth device based on nano-grade high-precision online control. According to the invention, besides a vacuum system, a gas path system, and a power supply control system which are connected and which are traditionally arranged outside a deposition chamber, the device comprises a novel design that a nano-grade high-precision servo system, a thin film morphology monitoring system, and a wide-range deposition stage temperature control system are combined and arranged in the deposition chamber. The nano-grade high-precision servo system is used for precisely controlling the distance, and nano-grade high-precision thin film deposition growth thickness and speed. With the nano-grade high-precision-control hot filament chemical vapor deposition thin film material growth device provided by the invention, position and thin film deposition growth speed and morphology can be controlled online with nano-grade high precision. With precise controlling over position and temperature, hot filament chemical vapor thin film deposition growth is always under optimal states such as fastest deposition speed, minimal defect, and the like.

The invention discloses a bipolar small-molecular luminescent material based on a heteroaromatic ring-fused-3-S,S-dioxodibenzothiophene unit, and a preparation method and an application thereof. Through a Suzuki coupling reaction, electron donor units are connected to two sides of the heteroaromatic ring-fused-3-S,S-dioxodibenzothiophene unit to prepare the luminescent material. The bipolar small-molecular luminescent material has good solubility, film-forming property and thin film morphological stability and also has excellent electron and hole transport performances, so that the material can balance injection and transportation of carriers, more electrons and holes are effectively compounded to generate excitons, and a mixing phenomenon with the transportation layer interface between the electrons and the holes, thereby improving luminescent efficiency of a device. A luminous layer, based on the material, is free of annealing treatment during preparation of electroluminescent devices, so that the production process is simple.

The invention relates to a conjugated organic molecule as well as a preparation method and application thereof. The structural formula of the organic conjugated molecule is shown in the following formula (1), Ar1 represents an electron withdrawing unit, Ar2 represents a side chain substitution unit, and R1 and R2 are independently selected from at least one of hydrogen atoms, alkyl with the carbon atom number being 2-20 and alkoxy with the carbon atom number being 2-20. The organic conjugated molecule has high visible light absorptivity, can form good complementation with the absorption of a low-band-gap acceptor material, and is beneficial to obtaining high short-circuit current. When the conjugated organic molecule and a non-fullerene receptor are blended to prepare an active layer of an organic solar cell, high photovoltaic efficiency can be obtained without any thin film morphology optimization means.

The invention belongs to the technical field of display devices, and particularly relates to a quantum dot light-emitting diode and a preparation method thereof. The preparation method of the quantum dot light-emitting diode comprises the following steps: providing a substrate, depositing a mixed solution containing a cross-linking agent and a hole function material on the substrate, carrying out annealing treatment, and then carrying out a cross-linking reaction under ultraviolet irradiation to obtain a hole function layer, wherein the hole functional material is an organic material containing benzyl. In the quantum dot light-emitting diode obtained by the preparation method, the formed hole function layer film has good stability and is not easily influenced by a solvent used for preparing the quantum dot light-emitting layer, so that the device has a smooth and complete film form, the light-emitting property of the device can be improved, and the service life of the device can be prolonged.

The invention provides a luminescent material and a preparation method thereof, and an organic light emitting diode using the same. The luminescent material has the advantages of single structure, definite molecular weight, relatively good solubility and film-forming property, and stable thin film morphology; the luminescent material has quite high decomposition temperature and relatively low sublimation temperature, is easily sublimated into a luminescent material with high purity, and can be applied to the small-molecular organic light emitting diode. According to the preparation method of the luminescent material, m-bromothiophenol and 2-fluoro-4-bromobenzonitrile are used as starting raw materials, an intermediate of the luminescent material is obtained through a series of simple reactions, and finally, the luminescent material is obtained through an Ullmann reaction or a Suzuki reaction; the steps are simple, and the yield is high. A luminescent layer of the organic light emitting diode contains the luminescent material and has relatively high luminous efficiency and stability.

The invention relates to a method for modifying a surface of an IOT electrode, which is applied to manufacture of organic photoelectric devices. The method is characterized in that after initial surface cleaning and ultraviolet ozone treatment are performed on an ITO surface, pentacene of which the thickness ranges from 0.5nm to 3.0nm is evaporated to serve as a positive electrode interface layer,then other functional layers of an organic photoelectric device are evaporated, and finally an OLED (Organic Light-Emitting Device) with a structure of ITO / Pentacene / NPB / Alq3 / LiF / metal electrode is manufactured, the obtained device is driven by a DC voltage, a driving voltage of the light-emitting device is about 2.9V, the maximum brightness is above 17000cd / m<2>, the maximum current efficiency and the maximum power efficiency respectively reach 4.54cd / A and 2.84lm / w; in comparison with a reference device which is not modified by the pentacene, a lighting voltage is basically unchanged, the maximum brightness increases by more than 30%, the current efficiency increases by 15%, and the power efficiency increases by 27%, at the same time, thin film dimensional stability of an organic functional layer can be improved, and stability of the whole device is also improved.

The invention discloses an experiment platform of non-contact measurement axial-symmetric fluid thin film morphology. The experiment platform comprises a fluid flow control device, a fluid thin film fabrication device, an image acquisition device and a fluid collection device, wherein the fluid thin film fabrication device comprises a drainage device arranged at the bottom of a top table plate ofa rack, the fluid flow control device comprises an injection pump, the injection pump is arranged on the top table plate and communicates with the drainage device by a guide pipe, the fluid collectiondevice comprises a liquid collector, the liquid collector is arranged below the drainage device and is arranged on a Z-axis lifting sliding table by an XY-axis translation sliding table, the Z-axis lifting sliding table is arranged on a bottom table plate of the rack, slim wires are arranged between the drainage device and the liquid collector in a traction way by clamping heads respectively arranged in the drainage device and the liquid collector, the image acquisition device comprises a camera and a backlight source, and the camera and the backlight source are arranged at a front position and a rear position of the slim wires and are arranged on the rack. By the acquired experiment image, the relevant dynamic characteristic of the axial-symmetric fluid thin film can be extracted, and the alignment is high.

The present invention relates to a film and a hidden switch structure including the same. The film of the present invention comprises: a base layer made of a transparent material; a first adhesive layer on which an adhesive is applied to the base layer to be stacked; a shielding layer stacked on and bonded to the first adhesive layer, and having an opaque paint applied thereto to process a symbolby laser; a second adhesive layer having an adhesive applied on the shielding layer to be stacked; and a sheet layer stacked on the second adhesive layer, and provided with a real wood in a thin filmshape. Therefore, the visibility is increased. The hidden switch structure including the film comprises: a first substrate on which an LED is installed; a second substrate coupled to be spaced apart from the first substrate, and having a touch sensor installed therein; an injected product having a prism embedded therein, and injection-molded to be stacked on the second substrate; and the film. Therefore, the degree of freedom of a design is increased.

The invention relates to the technical field of display, and provides a preparation method of a thin film and a light emitting diode. The preparation method of the thin film comprises the steps that dispersion liquid, a matrix and a first inert gas atmosphere are provided, the dispersion liquid comprises a p-type semiconductor material, the first inert gas atmosphere is doped with an aromatic compound, and the aromatic compound can disperse or dissolve the p-type semiconductor material; and performing film forming treatment on the dispersion liquid on a substrate in a first inert gas atmosphere to form a thin film. The thin film prepared by the method has a flat and compact surface, and when the thin film is applied to a hole function layer of a light-emitting diode, the thin film morphology of the hole function layer can be improved, and the interface resistance of the hole function layer and a light-emitting layer can be reduced, so that the hole transmission efficiency of a device is improved, and the hole transmission efficiency and electron transmission efficiency of the device are effectively balanced; and the photoelectric property and the service life of the device are improved.

The invention relates to a preparation method of a perovskite precursor solution and a perovskite thin film, and belongs to the technical field of perovskite solar cells. The technical problem to be solved by the invention is to provide the perovskite precursor solution. The perovskite precursor solution comprises a perovskite material and a mixed solvent, the mixed solvent is DMF (Dimethyl Formamide) and NMP (N-Methyl Pyrrolidone), and the volume ratio of the DMF to the NMP is 1: (0.01-0.13). According to the perovskite precursor solution, the problem of uneven perovskite nucleation caused by solvent volatilization can be avoided, a wet film post-treatment time window is prolonged, and large-area uniform film formation of perovskite prepared by a solution method is realized. The solution is used for preparing the perovskite thin film, the process is simple, the cost is low, the film forming window time, the thin film morphology and the uniformity degree of the thin film can be adjusted by adjusting the ratio of DMF to NMP, the solution is suitable for coating, blade coating and roll-to-roll printing technologies for large-area preparation of the perovskite thin film, the preparation process is simple and easy to control, and the method is suitable for large-area preparation of the perovskite thin film. And commercial manufacturing of large-area perovskite solar cells and assemblies is facilitated.

The invention discloses a sulfide annealing copper indium gallium sulfur solar cell thin film material preparation method after double-potential step method electrodeposition. The method comprises the steps that copper and gallium metal salt is used as a main raw material; the main raw material is dissolved in an ionic liquid at a certain concentration; a copper gallium precursor thin film is prepared on ITO conductive glass through double-potential cycle step method electrodeposition; sulfide annealing is carried out on the precursor thin film; in the annealing process, indium in the ITO conductive layer diffuses into the thin film; and finally a copper indium gallium sulfur thin film is generated. Compared with a traditional constant potential deposition technology, the method provided by the invention has the advantages that by controlling double potential pulse potential, controllable preparation of the crystalline phase, the composition, the morphology and the like of the thin film can be realized; pore structures are reduced; the thin film morphology is improved; the plating rate is improved; and hydrogen evolution reaction does not produce any adverse effect on the thin film in the deposition process. Compared with a high-vacuum vapor phase method, the method provided by the invention has the advantages of good film quality, low cost, high controllability and the like.

The invention belongs to the technical field of squaraine material preparation, and in particular relates to an asymmetric squaraine material and its preparation method and application. The present invention adopts to C 1 and C 2 The design and selection of the substituent make its spectral absorption peak in the blue-green light absorption region, which is used to prepare organic blue-green light-sensitive devices and meet the application requirements in the fields of blue-green light sensing and multi-channel optical communication; at the same time, the present invention provides The absorption half-width of the asymmetric squaraine material solution and the absorption half-width of the film form are both less than 110nm, and it has a very important application in the preparation of photodiodes. In addition, the material provided by the invention has strong stability and can meet various processes such as vapor deposition, spin coating, and inkjet printing.

The invention discloses a roughened tapered macro-bend optical fiber ethanol gas sensor based on a polypyrrole film modification, which relates to the field of optical fiber sensors. The sensor mainlyincludes a macro-bend optical fiber, a certain length of the macro-bend optical fiber is a tapered macro-bend structure, the tapered macro-bend structure is a residual core structure in which the fiber cladding and part of the fiber cores are removed after roughening processing, the polypyrrole film is attached to the surface of the tapered macro-bend structure to form an ethanol gas sensitive probe, the fiber part of the macro-bend optical fiber located at both ends of the tapered macro-bend structure is shielded by a black sleeve that shields external light, one end of the macro-bend optical fiber is connected with the LED light source, and the other end is connected with the optical power meter. Meanwhile, a preparation method and a detection method of the sensor are disclosed too. The detection method and the preparation method provided by the invention are relatively simple, the film shape is good, and can meet the detection requirements of arbitrary arrangement in a complex spatial structure, with simple structure and low cost.

The invention discloses a thin film form control device based on a visual camera shooting detection technology. The device comprises a meso-position air pipe, the meso-position air pipe is horizontally arranged above a working table, a meso-position vent pipe small hole is formed in the meso-position air pipe, adjustable side-position air pipe structures are installed on the two sides of the meso-position air pipe, the adjustable side-position air pipe structures and the meso-position air pipe are connected with a vacuum generator module, and a high-speed camera is arranged on one side of themeso-position air pipe. The device is simple in structure, and the maximum film bending radius which can be obtained under a certain negative pressure condition can be accurately obtained.