Highly flexible touch screen panel fabricated with silver-inserted transparent ITO triple-layer structures

Dual functions of light-emission and light-harvesting using organic donor and acceptor co-deposition

In this paper, the effect of doping concentration and layer thickness on the performance of tunnel junctions (TJs) is studied. We investigate the behavior of single, double and triple layer structures of TJs. Triple layer structure shows better performance in comparison with the other structures and can reach the higher tunneling current besides lower voltage drop. Also, the behavior of the triple layer TJ with different doping concentration profiles is studied. We propose a new normal distribution profile for doping concentration in multilayer TJs which shows better performance in comparison with the linear and graded doping concentration profiles. The higher $$\upalpha $$ parameters in normal distribution enhance the device performance with increasing the smoothness of doping variations in the center and edge of the TJ. Finally, we examine different thicknesses of triple layer TJ in order to achieve the optimum structure.

High-performance flexible Sn-doped In2O3 (indium tin oxide, ITO) electrodes were fabricated using a multicoating process on colorless polyimide (CPI) substrates for flexible perovskite solar cells (FPSCs). The effects of different coating sequences on the electrical, optical, and mechanical properties of the flexible ITO electrodes were thoroughly investigated after preparing them with direct-current magnetron sputtering (DMS) and arc plasma ion plating (APIP). Although both the sputtered ITO (SITO)/arc ion-plated ITO (AITO) film and the AITO/SITO film showed similarly low sheet resistance (18.69-25.29 Ω/sq) and high optical transmittance (94.96-96.85%), the coating sequence significantly affected the mechanical flexibility of the multicoated ITO films. The 120 nm-thick SITO/AITO electrode exhibited small outer and inner critical bending radii (3 mm and 3 mm, respectively) compared to the AITO/SITO electrode (4 and 5 mm, respectively). Owing to better adhesion of the arc-ion-plated ITO bottom layer and the amorphous structure of the top SITO layer, the SITO/AITO electrode exhibited excellent mechanical flexibility and durability. In addition, an FPSC using the SITO/AITO electrode achieved a higher power conversion efficiency (15.09%) than that with the AITO/SITO electrode (13.22%). This improvement was attributed to its high transmittance, low sheet resistance, smooth surface morphology, and enhanced hole collection efficiency. These findings highlight the efficacy of the combined DMS and APIP multicoating process for fabricating high-quality flexible ITO electrodes for high-performance FPSCs.

Resistance and transparency tunable Ag-inserted transparent InZnO films for capacitive touch screen panels

Face-to-face transferred multicrystalline ITO films on colorless polyimide substrates for flexible organic solar cells

Here, we demonstrate the fabrication of a flexible and transparent micro-supercapacitor (MSC), using colorless polyimide (CPI) via a direct laser writing carbonization (DLWC) process. The focused laser beam directly carbonizes the CPI substrate and generates a porous carbon structure on the surface of the CPI substrate. Fluorine, which is one of the chemical compositions of CPI, can enhance the specific area and the conductivity of the carbon electrode by creating micropores in carbon structures during carbonization. Thus, the fabricated carbonized CPI-based MSC shows enhanced specific capacitance (1.20 mF at 10 mV s−1) and better transmittance (44.9%) compared to the conventional PI-based MSC. Additionally, the fabricated carbonized CPI-based MSC shows excellent cyclic performance with minimal reduction (<~10%) in 3000 cycles and high capacitance retention under mechanical bending test conditions. Due to its high flexibility, transparency, and capacitance, we expect that carbonized CPI-based MSC can be further applied to various flexible and transparent applications.

The importance of transparent electrode technology for solar cells and perovskite solar cells will be introduced. First, we introduce the roll-to-roll sputtering technique and multilayer electrode for flexible solar cells. We fabricated flexible inverted solar cell (IOSC) modules (10 cm× 10 cm) on roll-to-roll (RTR) sputtered ITO/Ag/ITO multilayer cathodes. By using a pilot-scale RTR sputtering system equipped with mid-range frequency power for dual ITO targets and direct current power for the Ag target, we were able to continuously deposit a high-quality ITO/Ag/ITO multilayer on PET substrate with a width of 700 mm and length of 20,000 mm as a function of Ag thickness. To optimize the electrical and optical properties of the ITO/Ag/ITO multilayer, the thickness of Ag layer was varied by controlling of the DC power applied on Ag targets during the RTR sputtering process. At the Ag thickness of 12 nm, the ITO/Ag/ITO multilayer had a very low sheet resistance of 3.03 Ohm/square and high transmittance of 88.17%, which are better values than those of amorphous ITO film. Various bending test results showed that the high failure strain of the Ag inter layer led to good flexibility of the multilayer films. A strip-type ITO/Ag/ITO cathode was successfully patterned using a RTR wet etching process. Successful operation of flexible IOSC modules on RTR sputtered ITO/Ag/ITO cathodes indicate that the RTR sputtering technique is a promising coating process for fabrication of high-quality transparent and flexible cathodes and can advance the commercialization of cost-efficient flexible IOSCs. Second, we fabricated high-performance flexible CH3NH3PbI3 (MAPbI3) perovskite solar cells with a power conversion efficiency of 16.8% on transparent and flexible ITO electrode prepared by specially designed ion plating system. The ion plated ITO films on PET substrate showed a lower sheet resistance and higher optical transmittance than conventional sputtered ITO films because the high-energy input into a growing ITO film led to densification of the growing film during ion plating process. At optimal coating condition, the ion-plated ITO film with a thickness of 100 nm showed a sheet resistance of 15.75 Ohm/square and an optical transmittance of 84%, which are better than those of sputtered ITO film. Outer and inner bending tests demonstrated that the mechanical flexibility of the ion plated ITO film was superior to that of the conventional sputtered ITO film due to better adhesion between ion plated ITO and PET substrate. Flexible perovskite solar cells with the structure of Au/PTAA/MAPbI3/ZnO/ITO/PET showed a higher power conversion efficiency of 16.8% than sputtered ITO-based flexible perovskite solar cells (15.4%) due to lower sheet resistance and higher optical transmittance. Finally, we introduce a linear facing target sputtering technique to realize semi-transparent perovskite solar cells. By effective confinement of high density plasma between ITO targets, we can deposit plasma damage free IZTO electrode on layer. This indicates that linear facing target sputtering is a promising plasma damage free sputtering technique to deposit transparent electrode on perovskite active layer for high efficient semi-transparent perovskite solar cells.

HighlightsGraphene possesses high electronic mobility, minimal light absorbance, large surface area and exclusive mechanical properties.Graphene’s unique characteristics make it the perfect material for use in batteries, touch screens, transparent memory, and integrated circuits.The development of high-quality homogenous graphene, simple transfer processes, a lack of effective characterization methods, and high production costs prevent graphene from being widely used in the electronic industry.The production of large-area, nearly defect-free graphene using contemporary synthesis techniques, such CVD, holds great potential for the development of nanoelectronic devices.Graphene achieved a peerless level among nanomaterials in terms of its application in electronic devices, owing to its fascinating and novel properties. Its large surface area and high electrical conductivity combine to create high-power batteries. In addition, because of its high optical transmittance, low sheet resistance, and the possibility of transferring it onto plastic substrates, graphene is also employed as a replacement for indium tin oxide (ITO) in making electrodes for touch screens. Moreover, it was observed that graphene enhances the performance of transparent flexible electronic modules due to its higher mobility, minimal light absorbance, and superior mechanical properties. Graphene is even considered a potential substitute for the post-Si electronics era, where a high-performance graphene-based field-effect transistor (GFET) can be fabricated to detect the lethal SARS-CoV-2. Hence, graphene incorporation in electronic devices can facilitate immense device structure/performance advancements. In the light of the aforementioned facts, this review critically debates graphene as a prime candidate for the fabrication and performance enhancement of electronic devices, and its future applicability in various potential applications.

We introduce a new concept for transparent electrodes via the self-assembly of a silver nanowire (Ag NW) network with a cell shape. A transparent conductive network was achieved by forming an array of Ag NWs around droplets of a solvent with higher vapor pressure in Ag NWs ink. The difference in vapor pressure and viscosity of the solvent causes an Ag NWs network with a cell shape, and the cell size can be easily controlled from 10 to 100 μm using the solvent ratio. The cell network of Ag NWs with a high optical transmittance (>92%) and low sheet resistance (40 Ω/sq) was simply fabricated on flexible polymer films of large scale using a Meyer rod coating. In addition, we also studied and demonstrated the figure of merit of the transparent electrode between our method and a random Ag NWs network from the general method. The performance of the transparent electrode may be applied to a wide array of optoelectronic devices and can replace transparent conductive oxides such as Al-doped ZnO and indium tin oxide.

Ag grid/ITO hybrid transparent electrodes prepared by inkjet printing

Indium oxide, tin oxide and indium tin oxide nanostructure growth by vapor deposition

Transparent conductive films (TCFs) with low sheet resistance and high optical transmittance in the visible and infrared regions are essential components of a wide range of optoelectronic devices. Silver nanowires (AgNWs) have attracted significant attention due to their superior flexibility, conductivity, and transparency. However, TCFs prepared by commonly used film-forming methods such as spin coating suffer from a trade-off between conductivity and transmittance, which results in diminished device performance. Here, we report a layer-by-layer agitation-assisted alignment technique to fabricate highly aligned AgNWs films for transparent electrodes. The effects of solution concentration, rotation speed, and treatment time on the morphology, transmittance, and sheet resistance of the aligned AgNWs films were investigated systematically. Compared with randomly distributed AgNWs, optoelectronic performance was greatly improved, and the final film had a transmittance of 91.07% at 550 nm and a sheet resistance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$27.5~\Omega $ </tex-math></inline-formula>/sq. Research findings indicate that optimized AgNW electrodes can be successfully utilized to fabricate high-performance silicon-based photodetectors. Compared with previous designs, these detectors exhibit a 13.3% increase in the external quantum efficiency (EQE) at a wavelength of 850 nm. This study offers a low-cost and simple method for aligned AgNWs films, which has great potential for use in optoelectronic devices.

In article no. 1900010, Chaobin Yang, Michael J. Naughton and co-workers demonstrate two variants of an all-solution method to produce silver micro/nanowire films as transparent conductors. By integrating crackle photolithography-based microwires with nanowires and electroplate welding, the authors obtain transparent conductors with low sheet resistance (<1 ohm/sq.), high optical transmittance (>80%) and small domain size (∼10 μm2). It is shown that the samples can be transferred to flexible substrates, making a possible cost-effective candidate for flexible applications. The cover picture shows a photograph of an all-solution-processed micro/nanowire transparent conducting electrode on 100 mmdiameter glass, held in front of a building. Bottom left: Scanning electron microscopy (SEM) image of the silver micro/ nanowires, bottom right: SEM of a junction between two nanowires after electroplating.

An all‐solution‐processed transparent conductive electrode with sheet resistance one order of magnitude smaller than conventional nanowire‐based transparent conductors has been developed. This is achieved by integrating all‐solution produced microwires with a nanowire solution and electroplating and electrowelding. Advantages of the resulting transparent conductor are indium‐free, vacuum‐free, and lithographic‐facility‐free, and metallic‐mask‐free, with small domain size (≈10 μm2), low sheet resistance (Rs &lt; 1 Ω □−1), high optical transmittance (T &gt; 80%), mechanical flexibility, and scalability, thus making it an excellent replacement for ITO.

This study presents a transparent-patch antenna using a silver-mesh transparent electrode film with a high optical transmittance (87.7%), low haze (1.1%), and low sheet resistance (8.9 Ω/sq). The silver-mesh transparent electrode film is fabricated by using UV embossing and doctor blading without any high-temperature or vacuum processes. The UV resin pattern is transferred from a nickel mold to a plastic film, and then a silver paste is filled into the UV resin pattern. The transparent antenna patch and ground plane are obtained by repeating these processes on both sides of a single plastic film. The antenna patch is designed with a width of 44.8 mm and a height of 36.0 mm in order to obtain a resonant frequency at 2.45 GHz, which is a frequency of wireless LAN. As a result, the transparent-patch antenna has a reflection coefficient (S11 parameter) of -35.6 dB, a peak gain of -3.99 dBi, and a radiation efficiency of 6.2% at 2.45 GHz. Finally, a Wi-Fi router using the transparent-patch antenna is demonstrated.