Resistivity Indium Tin Oxide Research Articles

Rational design and fabrication of optically transparent broadband microwave absorber with multilayer structure based on indium tin oxide

A multilayer metamaterial absorber (MMA) with optically transparent and broadband microwave absorption characteristics based on Indium Tin Oxide ( ITO) and polymethyl methacrylate (PMMA) was designed and fabricated. The microwave absorption properties can be regulated by the resistance of ITO and the structural parameters of the unit cell. In the frequency range of 2.64–18 GHz, more than 90 % microwave absorption can be achieved. The microwave attenuation mechanism was investigated through equivalent electromagnetic parameters, impedance matching, electric and magnetic field distribution, power loss density and layer electric current at special frequencies. The microwave absorption performance at different incident angles under TE and TM polarization models was investigated to explore the angle-sensitive properties. The average transmittance of the absorber in the visible light wavelength range (400–800 nm) was also measured. The experimental and simulated microwave absorption rates are in accordance, indicating the potential application of the proposed absorber in the field of transparent microwave absorption. • Visible light transparent metamaterial absorber is fabricated. • The microwave absorbance over 90 % can be achieved within 2.64–18 GHz. • The metamaterial absorber has polarization insensitive and wide-angle stability properties. • Microwave attenuation mechanisms were investigated by surface electric current.

Design of an Optically Transparent Microwave Absorber Based on Coding Metasurface

In this paper, a metamaterial absorber with a checkerboard patterned ITO (indium tin oxide) film as the surface is obtained by using flexible and optically transparent wave-absorbing material ITO–PET (polyethylene terephthalate), and a coding arrangement of two basic coding units based on the APS-PSO (Array Pattern Synthesis -Particle Swarm Optimization) algorithm. The surface structure of the absorber consists of ITO rectangular patch structures and ITO circular patch structures (110 Ω/sq). The ITO rectangular patch structures and ITO circular patch structures are symmetrical. The middle layer is made up of two layers of PET and one layer of PMMA, and the bottom surface is covered with a layer of low square resistance ITO film (8 Ω/sq). The experimental results, which are consistent with the simulation results, show that the absorber has superior performance: over 90% absorptance in the 5.06–9.01 GHz band, high transmittance, and a −10 dBsm RCS (radar cross-section) reduction in the 5.3–8.7 GHz band. This design also has polarization insensitivity and angular stability.

Ultra-thin optically transparent broadband microwave metamaterial absorber based on indium tin oxide

Broadband metamaterial absorber (MMA) with optically transparent property is essential for solving the electromagnetic pollution problem at gigahertz. In this work, we designed and prepared a sandwich MMA consisting of high-transmittance substrate polymethyl methacrylate (PMMA), a periodically arranged indium tin oxide (ITO) film, and a low resistivity ITO reflective layer. The microwave absorbance over 90% can be achieved in the frequency range of 6–17.8 GHz. Wide-angular stability, good polarization insensitivity and optical transmittance to visible light (400–800 nm) are realized. The microwave attenuation mechanisms of the proposed MMA were investigated by surface current distribution and power loss density. The excellent microwave absorption and optical transmittance properties indicate the strong potential and feasibility of the designed MMA for the development of optically transparent microwave absorbing windows and devices.

Experimental Verification of Single‐Type Electron Population in Indium Tin Oxide Layers

Accurate determination of electronic transport properties of individual transparent conductive oxide layers, namely indium tin oxide (ITO), is essential for further development and design of photonic devices with ITO layer as a tunable ultrafast optoelectronic component. Precise magnetotransport measurements are here implemented to achieve carrier mobility distribution that gives insight into types and characteristics of carrier species. ITO thin films with various sheet resistance of ≈10, 75, and 350 Ω sq−1, respectively, are examined at near‐room temperature. Unimodal mobility distribution is revealed in ITO films, independently on their resistivity, with no evidence of unseparated contributions from surface or interface states. The electron mobility varies depending on ITO's resistivity, ranging from 36.8 to 47.2 cm2 V−1 s−1 at 300 K. Importantly, no minority hole conduction is present. The ITO thin films exhibit solely bulk‐like conduction with an absence of parallel conductions. In addition, the existence of single‐type electron population in ITO that can be viewed as an important validation of exclusively donor‐type defects and/or impurities contributing to total ITO conductivity is experimentally confirmed. These results indicate that ITO can be viewed as an integrated counterpart for photonic metadevices.

Sputtering under Mild Heating Enables High-Quality ITO for Efficient Semi-Transparent Perovskite Solar Cells

Semi-transparent perovskite solar cells (ST-PSCs) are promising in building-integrated photovoltaics (BIPVs) and tandem solar cells (TSCs). One of the keys to fabricate high-performance ST-PSCs is depositing efficient transparent electrodes. Indium tin oxide (ITO) is an excellent transparent conductive oxide with good light transmittance and high conductivity. However, the high sheet resistance of ITO sputtered at room temperature leads to the low fill factor (FF) and poor power conversion efficiency (PCE) of the ST-PSCs. Here, we study the effect of the sputtering temperature on the properties of ITO and the performance of ST-PSCs. We find that when the sputtering temperature increases from the room temperature to 70°C, the crystallinity of the sputtered ITO gradually improves. Therefore, the sheet resistance decreases and the corresponding device performance improves. However, once the sputtering temperature further increases over 70°C, the underlying hole transport layer will be damaged, leading to poor device performance. Therefore, the optimized mild heating temperature of 70°C is applied and we obtain ST-PSCs with a champion PCE of 15.21%. We believe this mild heating assisted sputtering method is applicable in fabricating BIPVs and TSCs.

Laser-induced graphene electrode based flexible heterojunction photovoltaic cells

Graphene based nanomaterials have attracted significant research interest due to their unique optoelectronic properties which can be tuned to tailor the functionalization in various photovoltaic (PV) applications. These PVs are capable of powering various wearable and flexible electronic devices such as touch-panels, light-emitting diodes (LEDs), sensors, high speed field effect transistors (FETs), etc., which can be a low-cost alternative to traditionally employed silicon solar cells. However, in terms of processing performance and electrical properties, current methods of manufacturing graphene-based PVs have numerous drawbacks. Therefore, there is a need for more effective fabrication methods with commercial feasibility and roll-to-roll processing of graphene-based PVs. This article is the first to present a laser-based patterning technique for fabricating graphene electrodes from polyimide that are compatible with flexible and thermally sensitive substrates for solar cell applications. A heterojunction PV, with ferroelectric Cr-doped BiFeO3 (BFCrO), was deposited on the flexible graphene as the energy harvesting layer sandwiched between p-NiO and n-WS2 window layers. Subsequently, its PV performance was compared with the similar multi-junction PV built on the Indium‑tin Oxide (ITO) one. The LIG electrode outperformed the ITO with its excellent stability, flexibility, and conductivity. The maximum power conversion efficiency (PCE) culminated was 5.20% which is around 5 folds enhancement when compared to the ITO based PV. Furthermore, after bending graphene electrode to 130°, the sheet resistance returned to its original value, while the resistance of ITO increased due to the cracking effect. With these unique properties, LIG electrodes can be promising for the development of flexible ferroelectric BFO based heterojunction PV devices.

Multi-spectral functional metasurface simultaneously with visible transparency, low infrared emissivity and wideband microwave absorption

In this paper, we propose the design of an optically transparent metasurface with simultaneously wideband microwave absorption and low infrared (IR) emissivity. To this end, two optically transparent functional layers are firstly designed using indium-tin-oxide (ITO), which can suppress IR emission and achieve wideband microwave absorption, respectively. The two functional layers are then combined together to construct the multispectral metasurface. By properly tuning the structural parameters and sheet resistance of ITO, a wide microwave absorption band can be achieved with absorption higher than 90%. Low IR emissivity of about 0.30 is obtained by controlling the occupation ratio of ITO on the front side structure of the metasurface. A prototype was fabricated and measured. The measured results show that the averaged transmittance of visible light through the metasurface reaches up to 62.4% and the high-efficiency microwave absorption can be achieved in 11.2–33.9 GHz, with absorption rate higher than 90%. Good consistency between the experiment and simulation results convincingly verifies the metasurface. Due to its multispectral compatibility, the proposed metasurface may find potential applications in multi-spectral stealth, camouflage, etc.

Optimal ITO transparent conductive layers for InGaN-based amber/red light-emitting diodes

Fabrication of indium tin oxide (ITO) was optimized for InGaN-based amber/red light-emitting diodes (LEDs). A radiofrequency sputtering reduced the sheet resistivity of ITO at low pressures, and a subsequent two-step annealing resulted in a low sheet resistivity (below 2×10-4 Ωcm) and high transmittance (over 98%) in the amber and red regions between 590 nm to 780 nm. Double ITO layers by sputtering could form an excellent ohmic contact with p-GaN. Application of the double ITO layers on amber and red LEDs enhanced light output power by 15.6% and 13.0%, respectively, compared to those using ITO by e-beam evaporation.

Sputtered indium tin oxide as a recombination layer formed on the tunnel oxide/poly-Si passivating contact enabling the potential of efficient monolithic perovskite/Si tandem solar cells

We focus on utilizing sputtered indium tin oxide (ITO) as a recombination layer, having low junction damage to an n-type silicon solar cell with a front-side tunnel oxide passivating electron contact, thereby enabling the development of a high efficiency monolithic perovskite/Si tandem device. High transparency and low resistivity ITO films are deposited via low power DC magnetron sputtering at room temperature onto a front-side thin SiOx/n+ poly-Si contact in a complete Cz n-Si cell with a back-side Al2O3/SiNx passivating boron-diffused p+-emitter on a random pyramid textured surface. We report the cell characteristics before and after ITO sputtering, and we find a cure at 250 °C in air is highly effective at mitigating any sputtering induced damage. Our ITO coated sample resulted in an implied open-circuit voltage (iVoc) of 684.7 ± 11.3 mV with the total saturation current density of 49.2 ± 14.8 fA/cm2, an implied fill factor (iFF) of 81.9 ± 0.8%, and a contact resistivity in the range of 60 mΩ-cm2 to 90 mΩ-cm2. After formation of a local Ag contact to the rear emitter and sputtered ITO film as the front-side contact without grid fingers, the pseudo-efficiency of 20.2 ± 0.5% was obtained with the Voc of 670.4 ± 7 mV and pseudo FF of 77.3 ± 1.3% under simulated one sun with the calculated short-circuit current density of 30.9 mA/cm2 from the measured external quantum efficiency. Our modelling result shows that efficiency exceeding 25% under one sun is practically achievable in perovskite/Si tandem configuration using the ITO recombination layer connecting a perovskite top cell and a poly-Si bottom cell.

A new strategy of binary-size particles model for fabricating fine grain, high density and low resistivity ITO target

A new strategy of 44&285 nm binary-size particles system has been proposed and discussed systematically for fabricating fine grain, high density and low resistivity indium tin oxide (ITO) target. Polyvinyl pyrrolidone (PVP) and Polyvinyl alcohol (PVA) were used as dispersant and adhesive. The effects from PVP, PVA, sintering temperature and holding time have been systematically investigated. The target, prepared by 44 nm powders with a sintering temperature of 1550 °C and a holding time of 10 h, shows a maximum relative density of 99.31% and a minimum resistivity of 4.17 × 10−4 Ω cm. Moreover, based on 285 nm powders, the target sintered at 1550 °C for 10 h shows a maximum relative density of 99.27% and a minimum resistivity of 4.11 × 10−4 Ω cm. Significantly, 44&285 nm binary-size particles system obviously increases the density and decreases the resistivity of target. And the maximum relative density, minimum resistivity and grain size are 99.57%, 0.92 × 10−4 Ω cm and 1.34 μm, respectively. In this model, the two designed particle sizes satisfy a formula of d=(233−1)×D. This new strategy contributes to preparing high-quality target, promoting the development of next generation ITO functional materials.

Fabrication of embedded metal-mesh flexible transparent conductive film via electric-field-driven jet microscale 3D printing and roller-assisted thermal imprinting

Transparent conductive films play a pivotal role in advanced optoelectronic devices, especially the flexible optoelectronic devices. The next-generation transparent conductive films require not only an optimal trade-off between the sheet resistance and optical transparency, but also an excellent flexibility. Although indium tin oxide (ITO) has been widely used in conventional transparent conductive films, the scarcity of indium, the brittleness and high sheet resistance of ITO hinder the further application in the emerging flexible optoelectronic devices. Among all the ITO substitutes, metal-mesh flexible transparent conductive film could be an ideal candidate due to its good flexibility and excellent photoelectric properties. However, the metal-mesh usually forms on the surface of the film, leading to high surface roughness, poor adhesion of the metal-mesh to the flexible substrate, and potential electrical short-circuits between the metal-mesh and a top electrode, which limits its applications for highly flexible electronic devices and optoelectronic devices. All these defects can be mitigated or optimized with embedded metal-mesh flexible transparent conductive films to achieve higher performance. Additionally, the embedded nature of the metal-mesh can make it have favorable resistance against moisture, oxygen, and chemicals. But the fabrication of embedded metal-mesh flexible transparent conductive film is more challenging. Despite some recent efforts to address these challenges, existing fabrication methods are still complex, with long cycles, high production costs and waste generation, especially they are difficult to realize the fabrication of large-area transparent conductive film. Therefore, new technologies to achieve high-efficiency, low-cost fabrication of large-area, high-performance embedded metal-mesh flexible transparent conductive film are needed. This paper proposes a new method for fabricating embedded metal-mesh flexible transparent conductive film based on electric-field-driven jet microscale 3D printing and roller-assisted thermal imprinting technology. First, the basic principle and process flow of the fabrication process are explained. Then, the effects and rules of the main process parameters (printing voltage, printing speed, printing pressure, imprinting temperature and imprinting force) on the precision and quality of the embedded metal-mesh flexible transparent conductive film are revealed via experiments for optimization of the process window. Finally, by using the optimized parameters on the electric-field-driven jet deposition micro-nano 3D printer and composite nanoimprint lithography machine independently developed by the research group, an embedded square metal-mesh flexible transparent conductive film with a pattern area of 70 mm ×70 mm, a line width of 20 μm and a pitch of 1000 μm is fabricated. It has a sheet resistance of 3.62 Ω/sq and a transmittance of 92.3% at a wavelength of 550 nm. In addition, the contact level of the metal-mesh to the substrate is up to 5B, the surface roughness value is 18.81 nm, and the change rate of the sheet resistance of the fabricated embedded metal-mesh flexible transparent conductive film after 1000 bending tests is less than 8%. The research shows that the proposed new method for fabricating embedded metal-mesh flexible transparent conductive film requires simple process steps and low production cost. The transparent conductive film produced has excellent photoelectric performance, low surface roughness and good mechanical flexibility. It provides a promising solution for high-efficiency mass production of high-performance transparent conductive films.

Optimization of low temperature RF-magnetron sputtering of indium tin oxide films for solar cell applications

In this work we have studied the influence of argon working pressure, substrate temperature, low power plasma irradiation and partial pressure of hydrogen in the RF-magnetron sputtering of indium tin oxide (ITO) thin films on glass substrates. This work aims at identifying the best conditions to achieve good quality ITO films at low temperature for deposition on heat-sensitive substrates. Four sets of samples were prepared which were characterized by X-ray diffraction (XRD), Van der Pauw and transmittance measurements. It was found that structural, electrical and optical properties of the films depend strongly on the deposition parameters. ITO films with a thickness of ~300 nm, displaying a sheet resistance of 68 Ω/sq and average transmittance, in the visible range, of about 90% were produced performing the deposition at low pressure and at room temperature. However, further improvements in the sheet resistance up to a factor of 3 were obtained by decreasing a little more the argon working pressure or applying a low power plasma irradiation or adding a partial pressure of hydrogen to the working gas. Films produced at low working pressures are crystalline and have [222] preferential orientation. The conductivity and transmittance of these films are higher than those of films deposited at high pressures. The electrical resistivity of the ITO thin films decreased sharply either with low power plasma irradiation or the addition of a partial pressure of H2 to the working gas. All the films showed an average transmittance of over 80% in the visible range. Therefore, as a result of this work we established that the addition of a small partial pressure of H2 to the working gas during growth allowed us to achieve the main aim of depositing low resistivity ITO films at low substrate temperature suitable for the envisaged applications. At the same time, we concluded that this approach leads to a drastic reduction in the amount of target surface conditioning required every time a new target was installed because it turns the properties of the ITO films more independent of the target surface properties.

Roll-to-Roll fabrication of ITO thin film for flexible optoelectronics applications: The role of post-annealing

We have developed and examined new and cost effective methods for fabrication indium tin oxide (ITO) film on flexible substrate. The ITO film is deposited to polyethylene terephthalate film using roll-to-roll (RTR) sputtering advanced technology. The film's properties are evaluated before and after heat treatment. Effect of post annealing time on the electrical, optical, structural and surface properties of RTR sputtered ITO films is estimated. In addition, mechanical flexibility of as-sputtered amorphous ITO and annealed crystalline ITO films are compared. It is estimated that post-annealing at 150 °C reduces sheet resistance and increase the optical transmittance of the ITO films. The best results are observed when annealing time is 60 min. In this case the sheet resistance of ITO is measured to be 125 Ω/sq. and optical transmittance is 87.3% at wavelength range from 380 nm to 780 nm. It is demonstrated successful operation of touch screen panels fabricated on annealed ITO film. It is estimated that post-annealing significantly improves ITO performance as compare of that as-deposited film. Based on Hall measurement and transmittance electron microscopy examinations, possible mechanism to explain the effect of post-annealing time on RTR sputtered ITO films is manifested.

Enhancement of optical transmittance and electrical resistivity of post-annealed ITO thin films RF sputtered on Si

This paper reports on the enhancement of optical transmittance and electrical resistivity of indium tin oxide (ITO) transparent conductive oxides (TCO) deposited by radio frequency (RF) sputtering on Si substrate. Post-annealing was conducted on the samples at temperature ranges of 500–700 °C. From X-ray diffraction analysis (XRD), ITO (2 2 2) peak was observed after post-annealing indicating crystallization phase of the films. From UV–vis measurements, the ITO thin film shows highest transmittance of more than 90% at post-annealing temperature of 700 °C as compared to the as-deposited thin films. From atomic force microscope (AFM), the surface roughness becomes smoother after post-annealing as compared to the as-deposited. The lowest electrical resistivity for ITO sample is 6.68 × 10−4 Ω cm after post-annealed at 700 °C that are contributed by high carrier concentration and mobility. The improved structural and surface morphological characteristics helps in increasing the optical transmittance and reducing the electrical resistivity of the ITO thin films.

The role of Ar plasma treatment in generating oxygen vacancies in indium tin oxide thin films prepared by the sol-gel process

Argon (Ar) plasma treatment was carried out to reduce the sheet resistance of indium tin oxide (ITO) thin films. The Ar plasma treatment did not cause any significant changes to the crystal structure, surface morphology, or optical properties of the ITO thin films. However, an X-ray photoelectron spectroscopy study confirmed that the concentration of oxygen vacancies in the film dramatically increased with the plasma treatment time. Thus, we concluded that the decrease in the sheet resistance was caused by the increase in the oxygen vacancy concentration in the film. Furthermore, to verify how the concentration of oxygen vacancies in the film increased with the Ar plasma treatment time, cumulative and continuous plasma treatments were conducted. The oxygen vacancies were found to be created by surface heating via the outward thermal diffusion of oxygen atoms from inside the film.

Indium–tin oxide films obtained by DC magnetron sputtering for improved Si heterojunction solar cell applications**Project supported by the National High Technology Research and Development Program of China (Grant No. 2011AA050501).

The indium–tin oxide (ITO) film as the antireflection layer and front electrodes is of key importance to obtaining high efficiency Si heterojunction (HJ) solar cells. To obtain high transmittance and low resistivity ITO films by direct-current (DC) magnetron sputtering, we studied the impacts of the ITO film deposition conditions, such as the oxygen flow rate, pressure, and sputter power, on the electrical and optical properties of the ITO films. ITO films of resistivity of 4×10−4 Ω·m and average transmittance of 89% in the wavelength range of 380–780 nm were obtained under the optimized conditions: oxygen flow rate of 0.1 sccm, pressure of 0.8 Pa, and sputtering power of 110 W. These ITO films were used to fabricate the single-side HJ solar cell without an intrinsic a-Si:H layer. However, the best HJ solar cell was fabricated with a lower sputtering power of 95 W, which had an efficiency of 11.47%, an open circuit voltage (Voc) of 0.626 V, a filling factor (FF) of 0.50, and a short circuit current density (Jsc) of 36.4 mA/cm2. The decrease in the performance of the solar cell fabricated with high sputtering power of 110 W is attributed to the ion bombardment to the emitter. The Voc was improved to 0.673 V when a 5 nm thick intrinsic a-Si:H layer was inserted between the (p) a-Si:H and (n) c-Si layer. The higher Voc of 0.673 V for the single-side HJ solar cell implies the excellent c-Si surface passivation by a-Si:H.

Important Implications of the Electrochemical Reduction of ITO

The electrochemical reduction of indium tin oxide (ITO) on glass is systematically studied. It is revealed that the light absorbance and electric resistance of ITO increases upon reduction. Scanning electron microscopy (SEM) images show that the integrate ITO films dissolve and form particles upon applying negative potentials. The particles consist of metallic In and Sn, as characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The reduction of ITO strongly depends on the electrolyte conditions, mainly pH and anions. The onset potential is found to shift negative as the pH of the electrolyte increases. NO3− ions are found to significantly inhibit the reduction of ITO, shifting the reduction potential negative by ca. 500mV as compared with SO42−, Cl− and Br−. It can also serve as inhibitor by adding very low concentration to the Cl−-dominant electrolyte. Moreover, it is found that the electrochemically reduced ITO show excellent non-linear optical performance, with transmittance tuneable by reduction potential and time. This suggests a promising useful application of the electrochemical reduction of ITO.

Improvement of optical and electrical properties of indium tin oxide layer of GaN-based light-emitting diode by surface plasmon in silver nanoparticles

We report on the effect of silver (Ag) nanoparticles on the optical transmittance and electrical conductivity of indium tin oxide (ITO) transparent conducting layer deposited on p-GaN layer of light-emitting diodes (LEDs). The sheet resistance of ITO and the series resistance of LEDs were decreased due to the increased electrical conductivity of ITO by Ag nanoparticles, compared with those of the LEDs with a bare ITO only. The ITO transmittance was also improved by localized surface plasmon resonance between the incident light and the randomly distributed Ag nanoparticles on ITO. The optical output power of LEDs with Ag nanoparticles on ITO was increased by 16% at 20mA of injection current.

Contact resistance of indium tin oxide and fluorine-doped indium oxide films grown by ultrasonic spray pyrolysis to diffusion layers in silicon solar cells

A simple method is described for estimating the contact resistance between a transparent conducting oxide film and a diffusion layer in a silicon solar cell. We have investigated the effect of film growth temperature on the contact resistance between n++-Si and p++-Si layers and In2O3:Sn (ITO) and In2O3:F (IFO) films grown by ultrasonic spray pyrolysis. The effect of growth temperature on the properties of the SiOx layer in IFO/SiOx/n++-Si structures has been studied by Fourier transform infrared absorption spectroscopy. The process for IFO deposition on n++-Si layers has been modified in order to reduce the IFO/SiOx/n++-Si contact resistance. The use of modified IFO has reduced the series resistance of an ITO/(p++nn++)Cz-Si/IFO bifacial solar cell for low-concentration applications by 0.13Ωcm2, from 0.39 to 0.26Ωcm2; extended its operating range of concentration ratios by a factor of 1.5, from 1–3.5× to 1–5.3×; and improved its efficiency in the operating range from 17.6–17.9 to 17.7–18.2%.

Reliability of thin films: Experimental study on mechanical and thermal behavior of indium tin oxide and poly(3,4-ethylenedioxythiophene)

In order to improve the performance of various flexible electronic devices, the research on the transparent conductive thin films becomes very intensive in the recent years. In this work, we studied mechanical and thermal behaviors of two types of transparent conductive thin films, Poly(3,4-ethylenedioxythiophene) (PEDOT) as an example on polymer conductive thin film, and indium tin oxide (ITO) as an example on transparent conductive oxide thin film. Both films are deposited on polyethyleneterephthalate (PET) substrate. Two sheet resistances for PEDOT (i.e., 150Ω/sq and 225Ω/sq) and one sheet resistance for ITO (i.e., 60Ω/sq) were involved in the study. PEDOT showed good mechanical properties with a small electrical resistance change and no clear cracks or deformation on the film surface under the condition of cyclic bending. However, the resistance of ITO significantly increased with the cyclic bending and cracks were seen initiated in the center of sample and propagated toward the edges. Further, design of experiment approach was used to study the effect of different cyclic bending parameters, such as bending diameter and frequency. Additionally, damp heat experiment on similar samples was conducted by applying 85°C temperatures and 85% relative humidity on them for 1000h. The electrical resistance was dramatically increased for both films. Scanning electronic microscopy (SIM), Energy Dispersive Spectrometry (EDX) and transmission tests were also used to determine the change of films’ compositions and transparencies.