Smart windows capable of dynamically controlling light transmission are gaining increasing attention as a means of reducing building energy consumption while improving indoor comfort. However, indium tin oxide (ITO), the most widely used transparent electrode in such devices, suffers from poor mechanical flexibility due to its intrinsic brittleness, limiting its use in curved or flexible window applications. Here, we demonstrate a flexible ITO/DPP hybrid transparent electrode, fabricated by depositing a dimethyl sulfoxide (DMSO)-doped PEDOT:PSS (DPP) layer on ITO, that achieves markedly improved bending durability while maintaining electro-optical performance comparable to bare ITO. The hybrid electrode with an optimized DPP thickness of 120 nm exhibited a sheet resistance of 23.3 Ω/sq., about 20% lower than that of ITO (29 Ω/sq.), while maintaining comparable visible-range transmittance. A polymer-dispersed liquid crystal (PDLC) device fabricated with this electrode showed only a slight decline in driving voltage and transmittance relative to ITO. Notably, its resistance change under repeated bending at a curvature radius of 30 mm was only 25.1%, less than half that of ITO (51.6%). These results suggest that the ITO/DPP hybrid electrode is a promising candidate for transparent electrodes in curved and flexible smart windows and other flexible optoelectronic devices.
e investigated the effects of post-annealing in vacuum, nitrogen, and hydrogen atmospheres on the structural, electrical, and optical properties of 600 nm thick Al-doped ZnO (ZnO:Al) thin films deposited by RF magnetron sputtering at room temperature. Post-annealing in hydrogen atmosphere at 400℃ for 1 hour showed the most significant improvement in electrical properties. Resistivity decreased from 9.11×10⁻³ to 1.4×10⁻³ Ω·cm, electron mobility increased from 4.11 to 18.23 cm²/V·s, and electron carrier concentration increased from 1.63×10²⁰ to 4.85×10²⁰ cm⁻³. In contrast, post-annealing in vacuum and nitrogen atmospheres resulted in degraded electrical properties due to oxygen and nitrogen chemisorption at grain boundaries. The enhancement in hydrogen-annealed films was attributed to the formation of additional oxygen vacancies and desorption of adsorbed oxygen species from grain boundaries. All films maintained excellent optical transparency of 80-90% in the visible range. The optical bandgap exhibited a blue-shift from 3.365 eV to 3.624 eV due to the Burstein-Moss effect induced by the increased electron carrier concentration. These results confirmed that hydrogen atmosphere post-annealing is the most effective method for enhancing the electrical conductivity of ZnO:Al thin films while maintaining high optical transparency.
The transparent electrode characteristics of the SnO₂/AgNi/SnO₂ (OMO) multilayer structures prepared by sputtering were investigated according to the annealing temperature. Ni-doped Ag of various compositions was selected as the metal layer and heat treatment was performed at 100~300℃ to evaluate the thermal stability of the metals. The manufactured OMO multilayer structures were heat treated for 6 hours at 400~600℃ in an N₂ atmosphere. The structural, electrical, and optical properties of the OMO structures before and after annealing were evaluated and analyzed using a UV-VIS spectrophotometer, 4-point probe, XPS, FE-SEM, etc. OMO with Ni-doped Ag shows improved performance due to the reduction of structural defects of Ag during annealing, but OMO structure with pure Ag shows degradation characteristics due to Ag diffusion into the oxide layer during high-temperature annealing. The figure of merit (FOM) of SnO₂/Ag/SnO₂ was highest at room temperature and gradually decreased as the heat treatment temperature increased. On the other hand, the FOM value of SnO₂/AgNi/SnO₂ mostly showed its maximum value at high temperature(~550℃). In particular, the FOM value of SnO₂/Ag-Ni (3.2 at%)/SnO₂ was estimated to be approximately 2.38×10-2 Ω-1. Compared to transparent electrodes made of other similar materials, the FOM value of the SnO₂/Ag-Ni (3.2 at%)/SnO₂ multilayer structure is competitive and is expected to be used as an alternative transparent conductive electrode in various devices.
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Strategies and Multilayer Architectures for Decoupling Conductivity–Transparency Trade-Off Xi Cao, Yuying Feng, Zhengjie Guo, Xuezhi Li, Yixian Xie, Chenyao Huang, Yikun Yang, Fuyueyang Tan, Kaiquan Lei, Zaijin Li, Yi Qu, Lin Li Coatings.2026; 16(8): 915. CrossRef
Nickel oxide is a nonstoichiometric transparent conductive oxide with p-type conductivity, a wide-band energy gap of 3.4~4.0 eV, and excellent chemical stability, making it a very important candidate as a material for bipolar devices.P-type conductivity in Transparent Conductive Oxides (TCO) is controlled by the oxygen vacancy concentration. During the TCO film deposition process, additional oxygen diffusing into the NiO structure causes the formation of Ni 3p ions and Ni vacancies. This eventually affects the hole concentration of the p-type oxide thin film. In this work, the surface morphology and the electrical characteristics were confirmed in accordance with the annealing atmosphere of the nickel oxide thin film.
The deposition of indium zinc oxide (IZO) thin films was carried out on substrate at room temperature by RF magnetron sputtering. The effects of substrate temperature, RF power and deposition pressure were investigated with respect to physical and optical properties of films such as deposition rate, electrical properties, structure, and transmittance. As the RF power increases, the resistivity gradually decreases, and the transmittance slightly decreases. For the variation of deposition pressure, the resistivity greatly increases, and the transmittance is decreased with increasing deposition pressure. As a result, it was demonstrated that an IZO film with the resistivity of 3.89 × 10-4 Ω·cm, the hole mobility of 51.28 ㎠/Vs, and the light transmittance of 86.89% in the visible spectrum at room temperature can be prepared without post-deposition annealing.
Laser-induced plasmonic sintering of metal nanoparticles (NPs) is a promising technology to fabricate flexible conducting electrodes, since it provides instantaneous, simple, and scalable manufacturing strategies without requiring costly facilities and complex processes. However, the metal NPs are quite expensive because complicated synthesis procedures are needed to achieve long-term reliability with regard to chemical deterioration and NP aggregation. Herein, we report laser-induced Ag NP self-generation and sequential sintering process based on low-cost Ag organometallic material for demonstrating highquality microelectrodes. Upon the irradiation of laser with 532 nm wavelength, pre-baked Ag organometallic film coated on a transparent polyimide substrate was transformed into a high-performance Ag conductor (resistivity of 2.2 × 10-4 Ω·cm). To verify the practical usefulness of the technology, we successfully demonstrated a wearable transparent heater by using Ag-mesh transparent electrodes, which exhibited a high transmittance of 80% and low sheet resistance of 7 Ω/square.
This paper describes why we must use graphene materials for solar cells and biosensors. It has been superior in several properties such as super-thin film, higher tensile strength, high current density, high thermal conductivity, and high mobility. Therefore, graphene is one of the emerging advanced materials because of its applicability in various electronic device applications. We investigated the requirements of graphene materials for the application of solar cells and biosensors. In addition, we discussed the research trends such as transducers in biosensors and transparent electrodes in solar cells. The research on graphene materials and their application will be beneficial and helpful for the near future.
In this study, we investigated the optical, electrical and exothermic characteristics of ITO/Ag/ITO multilayer structures prepared with various Ag thicknesses on quartz and PI substrates. The transparent conducting properties of the ITO/Ag/ITO multilayer films depended on the thickness of the mid-layer metal film. The ITO/Ag (14 nm)/ITO showed the highest Haccke’s figure of merit (FOM) of approximately 19.3×10-3 Ω-1. In addition, the exothermic property depended on the substrate. For an applied voltage of 3.7 V, the ITO/Ag (14 nm)/ITO multilayers on quartz and PI substrates were heated up to 110℃ and 200℃, respectively. The bending tests demonstrated a comparable flexibility of the ITO/Ag/IT multilayer to other transparent electrodes, indicating the potential of ITO/Ag/ITO multilayer as a flexible transparent conducting heater.
In this study, composite transparent electrodes were fabricated either from a conductive polymer poly(3,4- ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) or silver nanowire (AgNW). Three transparent electrodes such as PEDOT:PSS, PEDOT:PSS and AgNW mixture, and AgNW were fabricated. As for a transparent electrode, measured sheet resistance values were 89.6, 60.6 and 28.6 Ω/sq, and the transmittance values were 80.2, 82.0 and 83.8% while surface roughness (Rq) values were 4.1, 8.1, 20.4 nm for PEDOT:PSS, PEDOT:PSS and AgNW mixture, and AgNW, respectively. To verify the overall performance of these composite electrodes, we applied these electrodes to the top electrode of the solution-processed organic solar cells (OSCs). PEDOT:PSS provided the best performance with a fill factor (FF) of 51.2% and a photoconversion efficiency (PCE) of 2.2%, while traditional metal top electrode OSC provided FF of 60.5% and PCE of 3.1%.
A multiple-electrode-type electronic paper film can implement a single color and control the transparency, as it has multiple electrodes in one cell. Therefore, it can be used as a transparent display. In this paper, we explain the structure and driving method of a transparent electronic paper display, and then propose a control method of transmittance. Subsequently, we verify the theory by measuring the transmittance via experiment. Thus, by changing the manner of applying the voltage to three lower electrodes and one upper electrode, transmittance in eight cases could be realized. It was confirmed that the transmittance derived from the experiment could be controlled from a minimum of 6.75% to a maximum of 71.18%.
Privacy films are typically manufactured by combining black resin and transparent louver-shaped patterns. The use of black resin results in excellent light-shielding. However, black resin can reduce the transmittance of privacy films at the front viewing angle. In this study, we applied SiO2/SiON multi-layer thin films on a privacy film to maintain transmittance at the front viewing angle and improve light-shielding at the side viewing angle. We determined the optimum combination of thicknesses of the SiO2/SiON multi-layer stacks to increase the overall transmittance; the light shielding could be maximized at the side viewing angle.
In this study, oxide/metal/oxide-type transparent electrodes based on Al and ZnO were investigated. Thin films of these materials were sputter-deposited at room temperature. To evaluate the thickness dependence of the oxide layers, the top and bottom ZnO layers were varied in the range of 5~80 nm and 2.5~20 nm, respectively. When the thicknesses of the top and bottom ZnO layers were fixed at 30 nm and 2.5 nm, a maximum transmitance of 66% and sheet resistance of 16.5 Ω/□ were achieved, which is significantly improved compared with the Al layer without top and bottom ZnO layers showing a maximum transmitance of 44.3% and sheet resistance of 44 Ω/□.
In this study, functional transparent conducting layers were investigated for Si-based photoelectric applications. Double transparent conductive oxide (TCO) films were deposited on a Si substrate in the sequence of indium tin oxide (ITO) followed by aluminum-doped zinc oxide (AZO). First, we observed that the conductivity and transparency of AZO dominate the overall performance of the double TCO layers. Secondly, the double layered TCO film (consisting of AZO/ITO) deposited by sputtering was compared to a AZO-only film in terms of their optical and electrical properties. We prepared three different AZO films: ITO:3min/AZO:10min, ITO:5min/AZO:7min, and ITO:7min/AZO:4min. The results show that the optical properties (transmittance, absorbance, and reflection) can be controlled by the film composition. This may provide a significant pathway for the manipulation of the optical and electrical properties of photoelectric devices.
Transparent conductive thin films (TCFs) are essential materials for solar cells, organic light-emitting diodes, and display panels. Indium tin oxide (ITO) is one of the most widely used commercial materials to create TCFs’; however, new materials that can possibly replace ITO at a lower cost and/or those possessing mechanical flexibility are urgently needed. Silver nanowire (AgNW) is one of those promising materials, as it is less expensive and possesses superior mechanical flexibility as compared to ITO. We used AgNW and sol-gel ZnO to fabricate composite thin films by spray coating. We propose two spray-coating methods: the ‘metal－organic chemical vapor deposition (MOCVD)/AgNW’ method and the Mixture method. These two methods are expected to be commercialized for high-quality and low-cost products, respectively.
Herein we studied the electrical and optical properties of indium tin oxide ITO/Ag/ITO multilayer thin films for application in transparent conducting electrodes. The ITO and Ag thin films were deposited onto soda lime glass (SLG) using radiofrequency and DC-sputtering methods, respectively. The as-synthesized ITO/Ag/ITO multilayer thin films were analyzed using 4-point probe, UV-Visible spectroscopy, and Hall measurement. We observed a rapid increase in electron concentration with increasing Ag thickness. However, electron mobility decreased with increasing Ag thickness. Finally, ITO/Ag/ITO multilayer thin films showed a characteristic low sheet resistance of 18 Ω/sq and high optical transmittance value (80%) with variation of Ag thickness (5~10 nm).
The proposed stretchable transparent electrodes based on silver nanowires (AgNWs) were prepared on a polyurethane (PU) substrate. In order toavoid the surface roughness caused by the silver nanowires, a titanium oxide (TiO2) buffer layer was addedby coating and heating the organometallic sol-gel solution. The fabricated stretchable electrodes showedan electrical sheet resistance of 24 Ωsq-1, 78% transmittance at 550 nm, and an average surface roughness below 5 nm. Furthermore, the AgNW-based electrode maintained its initial electrical resistance under 130% strain testing conditions, without the assistance of additional conductive polymer layers. In this paper, the critical role of the TiO2 buffer layer between the AgNW network and the PU substrate has been discussed.
A hybrid transparent electrode was fabricated with graphene and silver nanowires (Ag NWs). Three different processes were used to fabricate the hybrid electrode. Measurements of the sheet resistances, transmittances, and surface roughnesses of the hybrid electrodes were used to identify the optimal fabrication process. The surface roughness of the hybrid electrodes with Ag NWs embedded in a transparent polymer matrix was significantly lower than that of the other hybrid electrodes. A hybrid electrode fabricated by transferring graphene onto Ag NWs after spin-coating the Ag NWs onto the substrate showed the lowest sheet resistance. The transmittance of the hybrid electrodes was comparable to that of Ag NW electrodes.
Transparent film heaters employing silver nanowires (Ag NWs) have attracted increasing attention because of their widespread applications. However, the low thermal resistance of Ag NWs limits the maximum operating temperature of the Ag NW film heater. In this study, Ag NW film heaters with high mechanical and thermal stability were successfully developed. The thermal power-out characteristics of the Ag NW heaters were investigated as a function of the Ag NW density. The results revealed that the prepared flexible Ag NW heater possessed high thermal stability over 190℃ owing to ZnO encapsulation. This indicates that the Ag NW film with excellent thermal stability have remarkably high potential for use as electrodes in film heaters operating at high temperatures.
Because silicon thin film solar cells have a high absorption coefficient in visible light, they can absorb 90% of the solar spectrum in a 1-μm-thick layer. Silicon thin film solar cells also have high transparency and are lightweight. Therefore, they can be used for building integrated photovoltaic (BIPV) systems. However, the contact electrode needs to be replaced for fabricating silicon thin film solar cells in BIPV systems, because most of the silicon thin film solar cells use metal electrodes that have a high reflectivity and low transmittance. In this study, we replace the conventional aluminum top electrode with a transparent aluminum-doped zinc oxide (AZO) electrode, the band level of which matches well with that of the intrinsic layer of the silicon thin film solar cell and has high transmittance. We show that the AZO effectively replaces the top metal electrode and the bottom fluorine-doped tin oxide (FTO) substrate without a noticeable degradation of the photovoltaic characteristics.
Indium tin oxide (ITO) thin films show a low sheet resistance and high transmittance in the visible range of the spectrum. Therefore, they play an important role as transparent electrodes for flat panel displays. However, their resistivity is rather high for use as a transparent electrode in large displays. One way to improve electrical and optical properties in large displays is to use ITO/Ag/ITO multilayer films. ITO/Ag/ITO multilayer films have lower sheet resistance than single layer ITO films with the same thickness. Prior to the ITO/Ag/ITO multilayer experiments, optimal condition for thickness change are necessary. Their thicknesses were deposited differently in order to analyze electrical and optical properties. However, when optimal single film characteristics are applied to ITO/Ag/ITO multilayer films, other phenomena appeared. After analyzing the electrical and optical properties by changing ITO and Ag film thickness, ITO/Ag/ITO multilayer films were optimized. By combining ITO film at 586 Å and Ag film at 10 nm, the ITO/Ag/ITO multilayer films showed optimized high optical transmittance of 87.65%, and the low sheet resistance of 5.5 Ω/sq.
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The Electrical, Optical, Heating Property and Electromagnetic Wave Shield Effect of TiO2/Ag/TiO2 Thin Films Jiho Kim, Yu-Sung Kim, Jin-Young Choi, Yeon-Hak Lee, Young-Min Kong, Daeil Kim Korean Journal of Metals and Materials.2024; 62(9): 735. CrossRef
The dielectric thin films applied to multi-colored semitransparent thin film solar cells have been extensively studied. In this work, we prepared GeSbTe and GeTe chalcogenide thin films using magnetron sputtering, and investigated their optical and phase-change properties to replace the dielectric films. The changes of surface morphology, sheet resistance, and X-ray diffraction of the Te-based chalcogenide films support the fact that the amorphous stability of GeTe films is superior to that of GeSbTe films. While both amorphous GeSbTe and GeTe films thinner than 30 nm have optical transparency between 5% and 60%, GeTe films transmit more visible light than GeSbTe films. It is confirmed by computer simulation that the color of semitransparent silicon thin film solar cells can be adjusted with the addition of GeSbTe or GeTe films. Since it is possible to adjust the contrast of the solar cells by exploiting the phase-change property, the two kinds of chalcogenide films are anticipated to be used as an optical layer in semitransparent solar cells.
In this study, we fabricate transparent and bendable a-IGZO (amorphous indium gallium zinc oxide) TFTs (thin-film transistors) with a-IZO (amorphous indium zinc oxide) transparent electrodes on plastic substrates and investigate their electrical characteristics under bending states. Our a-IGZO TFTs show a high transmittance of 82% at a wavelength of 550 nm. And these TFTs have an Ion/Ioff ratio of 1.8×108, a field effect mobility of 15.4 cm2/V·s, and a subthreshold swing of 186 mV/dec. The good electrical characteristics are retained even after bending with a curvature radius of 18 mm corresponding to a strain of 0.5% owing to mechanical durability of the transparent electrodes used in this study.
The basic characteristics of glass are highly fragile and brittle consequences the ultimate purpose of glass manufacturing is to make a transparent glass with complex shape. In order to solve this problem, mechanical properties of glass can be increased by crystallization of its amorphous glass. However, glass-ceramics has become opaque through crystallization process due to the distracted interface of glass by precipitated particles. This study has been investigated thermal processing conditions of LAS transparent glass-ceramic by using DTA (differential thermal analysis), in order to control size of precipitated particle and then fabricate transparent glass-ceramic. DTA indicated that crystallization peak area was declined with increased nucleation temperature. Subsequently, we have been established optimum temperature for crystallization depending on the nucleation temperature. The transmission and thermal expansion were measured after crystallization, and the size of precipitated particle was identified in range of 20~100 nm by FE-SEM. In addition, by setting the optimized crystallization condition, with high transmission and low thermal expansion glass was synthesized through this experiment.
We have studied commercialization and process optimization of protective film on transparent conductive coated substrate, nano silver on flexible PET (poly ethylene terephthalate), by means of roll-to-roll micro-gravure coater. Nanosilver on flexible PET substrate is potential materials to replace ITO (indium tin oxide). Protective film is most important to maintain unique silver pattern on top of transparent PET. PSA pressure sensitive adhesives) was developed solely for nano silver on PET and protective film was successfully laminated. We have optimized all process conditions such as coating thickness, line speed and aging time & temperature via experimental design. Transparent conductive film and its protective film developed in this research are commercially available at this moment.
Highly optical transparent photoelectric devices were realized by using a transparent metal-oxide semiconductor heterojunction of p-type NiO and n-type ZnO. A functional template of ITO nanowires (NWs) was applied to this transparent heterojunction device to enlarge the light-reactive surface. The ITO NWs/n-ZnO/p-NiO heterojunction device provided a significant high rectification ratio of 275 with a considerably low reverse saturation current of 0.2 nA. The optical transparency was about 80% for visible wavelengths, however showed an excellent blocking UV light. The nanostructured transparent heterojunction devices were applied for UV photodetectors to show ultra fast photoresponses with a rise time of 8.3 mS and a fall time of 20 ms, respectively. We suggest this transparent and super-performing UV responser can practically applied in transparent electronics and smart window applications.
In this study ensuring a filming technology is attempted through dispersion technologies and mixing polymer scaffolds in order to produce films based on the nanowaires obtained from chitin. In addition this study proposes technologies in measuring and improving characteristics of films produced using nanowires and for applying electric conductivity to the films as a chemical and physical manner. Also, a possibility in applications of mass productive films or substrates to producing flexible and transparent films is proposed. In the experiment implemented in this study, it is verified that developments of high strength, high transparency, and high flexibility films can be developed through combining it with producing flexible and transparent films.
We have investigated the properties of Al-doped ZnO (AZO) thin films as functions of atomic layer deposition (ALD) oxidants. AZO transparent conducting oxides (TCOs) layer was deposited by ALD with adding trimethylaluminum (TMA) and diethylzinc (DEZn). AZO films were deposited at low temperature with H2O and O3 as oxidants. Electrical, optical and structural properties of AZO thin films were investigated by 4-point probe, Hall effect measurement, UV-VIS, and AFM. Microstructure and atomic bonding states were investigated by HRXRD and XPS. The resistivity of AZO films grown using H2O was lower than the films grown using H2O and O3, by approximately two orders of magnitude. The differences in oxygen vacancy peak intensity of AZO films were correlated to the optical and electrical properties.
We have studied structural, optical and electrical properties of In-Ga-doped ZnO (IGZO) thin films. The IGZO thin films were deposited on the corning 1737 glass by RF magnetron sputtering method. The RF power in sputtering process was varied as 30, 50, 70, and 90 W respectively. All of the IGZO thin films transmittance in the visible range (400 nm ~ 800 nm) was above 83%. XRD analysis showed the IGZO thin films amorphous structure of the thin films without any peak. And also IGZO thin film have low resistivity (1.99×10-3 Ωcm), high carrier concentration (6.4×1020 cm-3), and mobility (10.3 cm2V-1s-1). By the studies we found that IGZO transparent thin film can be used as optoelectronic material and introduced application possibility for future electronic devices.
Zinc tin oxide transparent thin film transistors (ZTO TTFTs) were fabricated by using n`` Si wafers as gate electrodes. Indium (In), aluminum (Al), indium tin oxide (ITO), silver (Ag), and gold (Au) were employed for source and drain electrodes, and the mobility and the threshold voltage of ZTO TTFTs were observed as a function of electrode. The ZTO TTFTs adopting In as electrodes showed the highest mobility and the lowest threshold voltage. It was shown that Ag and Au are not suitable for the electrodes of ZTO TTFTs. As the results of this study, it is considered that the interface properties of electrode/ZTO are more influential in the properties of ZTO TTFTs than the conductivity of electrode.
Zinc tin oxide transparent thin film transistors (ZTO TTFTs) were fabricated on oxidized n+ Si wafers. The thickness of 30 nm Al2O3 films were deposited on the oxidized Si wafers by atomic layer deposition, which acted as the gate insulators of ZTO TTFTs. The Al2O3 films were rapid-annealed at 400 , 600 , 800 , and 1,000 , respectively. Active layers of ZTO films were deposited on the Al2O3/SiO2 coated n+ Si wafers by rf magnetron sputtering. Mobility and threshold voltage were measured as a function of the rapid-annealing temperature. X-ray photoelectron spectroscopy (XPS) were carried out to observe the chemical bindings of Al2O3 films. The annealing effects of gate-insulator on the properties of TTFTs were analyzed based on the results of XPS.
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