Flexible, Transparent and Conductive Metal Mesh Films with Ultra‑High FoM for Stretchable Heating and Electromagnetic Interference Shielding

Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittance remains a significant challenge.Herein,a flexible,transparent,and conductive copper(Cu)metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique.The Cu mesh film shows an ultra-low sheet resistance(0.18Ω□^(-1)),high transmittance(85.8%@550 nm),and ultra-high figure of merit(>13,000).It also has satisfactory stretchability and mechanical stability,with a resistance increases of only 1.3%after 1,000 bending cycles.As a stretchable heater(ε>30%),the saturation temperature of the film can reach over 110°C within 60 s at 1.00 V applied voltage.Moreover,the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5μm.As a demonstration,it is used as a transparent window for shielding the wireless communication electromagnetic waves.Therefore,the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.

Dual functional transparent film for proximity and pressure sensing

Over the past few years, the rapid development of tactile sensing technology has contributed significantly to the realization of intuitional touch control and intelligent human-machine interaction. Apart from physical touch or pressure sensing, proximity sensing as a complementary function can extend the detection mode of common single functional tactile sensors. In this work, we present a transparent, matrix-structure dual functional capacitive sensor which integrates the capability of proximity and pressure sensing in one device, and the excellent spatial resolution offered by the isolated response of capacitive pixels enables us to realize precise location identification of approaching objects and loaded pressure with fast response, high stability and high reversibility.

Fabrication of high-quality silver nanowire conductive film and its application for transparent film heaters

Here,we report a facile method to produce pure silver nanowires(Ag NWs)with high yield.A highly conductive dispersant was used to ensure uniform dispersion of the Ag NWs.Without any posttreatment,the Ag NW networks,deposited on flexible substrates,showed excellent optoelectrical performance owing to minimal junction resistance between the Ag NWs.To explore their potential in flexible optoelectronic devices,a transparent film heater was constructed based on the present Ag NW networks.The heater could achieve rapid response at low input voltage and reach a relatively high temperature in a short response time.Since this high-quality Ag NW film exhibits relatively low production costs and fast production time,it may have value for future electronic industry applications.

Nanofiber-based transparent film with controllable optical transparency adjustment function for versatile bionic applications

As a new favorite in the field of smart materials,smart windows,with visual stimulus sensing functions,have attracted extensive attention for their high transparency,sensitive response to environmental stimulus,and reversible changes in light transmittance.In this paper,the PVA-coPE nanofiber film,which was completely opaque like paper,was used as filling phase and reacted with water-soluble N-vinyl-2-pyrrolidone(NVP)by photopolymerization to produce a flexible transparency polyvinyl pyrrolidone/spraying PVA-co-PE nanofiber films(PVP/SPNFs)composite film.Among them,the small size effect of PVA-coPE nanofibers played a pivotal role in improving the film's transparency.Nevertheless,the PVP's reversible adsorption-desorption behavior of water molecules made its refractive index change dynamically and reversibly,which led to the visual transition of composite film from transparent to opaque just like that of electronic smart windows.Additionally,the reversible transition rate of film's transparency can be effectively regulated by the nanofiber stack structure.This new design of transparency visualization transforms composite film in response to humidity,innovates the electrically controlled smart windows on energy and realizes the effective utilization of natural resources such as water and humidity,which has a great application prospect in the field of flexible optoelectronic devices,intelligent buildings,and smart writing.

Sol-gel Processing of a Transparent Upconversion Luminescent Film with β-Na YF_4:Yb^(3+), Er^(3+) Microrods as Activator

β-Na YF4:Yb3+,Er3+ microrods were synthesized through hydrothermal methods. Polyethylene glycol with molecular weight of 6000 was used as surfactant. A series of transparent silica gel films with upconversion luminescence property was prepared through sol-gel method; the prepared β-Na YF4:Yb3+,Er3+ microrods were used as activator. The silica gel films show strong upconversion emission under excitation of 980-nm laser beam.

Effects of Atomic Oxygen Irradiation on Transparent Conductive Oxide Thin Films

Transparent conductive oxide （TCO） thin film is a kind of functional material which has potential applications in solar cells and atomic oxygen （AO） resisting systems in spacecrafts. Of TCO, ZnO：Al （ZAO） and In2O3：Sn （ITO） thin films have been widely used and investigated. In this study, ZAO and ITO thin films were irradiated by AO with different amounts of fluence. The as-deposited samples and irradiated ones were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and Hall-effect measurement to investigate the dependence of the structure, morphology and electrical properties of ZAO or ITO on the amount of fluence of AO irradiation. It is noticed that AO has erosion effects on the surface of ZAO without evident influences upon its structure and conductive properties. Moreover, as the amount of AO fluence rises, the carrier concentration of ITO decreases causing the resistivity to increase by at most 21.7%.

Effect of RF power on the properties of transparent conducting zirconium-doped zinc oxide films prepared by RF magnetron sputtering

Transparent and conducting zirconium-doped zinc oxide films with high transparency and relatively low resistivity have been successfully prepared by radio frequency （RF） msgnetron sputtering at room temperature, The RF power is varied from 75 to 150 W. At first the crystallinity and conductivity of the film are improved and then both of them show deterioration with the increase of the RF power, The lowest resistivity achieved is 2.07 × 10^-3Ωcm at an RF power of 100W with a Hall mobility of 16cm^2V^-1s^-1 and a carrier concentration of 1.95 × 10^20 cm^-3. The films obtained are polycryetalline with a hexagonal structure and a preferred orientation along the c-axis, All the films have a high transmittance of approximately 92% in the visible range. The optical band gap is about 3.33 eV for the films deposited at different RF powers.

Properties of doped ZnO transparent conductive thin films deposited by RF magnetron sputtering using a series of high quality ceramic targets

To obtain high transmittance and low resistivity ZnO transparent conductive thin films,a series of ZnO ceramic targets（ZnO：Al,ZnO：（Al,Dy）,ZnO：（Al,Gd）,ZnO：（Al,Zr）,ZnO：（Al,Nb）,and ZnO：（Al,W）） were fabricated and used to deposit thin films onto glass substrates by radio frequency（RF） magnetron sputtering.X-ray diffraction（XRD） analysis shows that the films are polycrystalline fitting well with hexagonal wurtzite structure and have a preferred orientation of the（002） plane.The transmittance of above 86% as well as the lowest resistivity of 8.43 × 10^-3 Ω·cm was obtained.

Preparation and characterization of ZnO/Cu/ZnO transparent conductive films

ZnO/Cu/ZnO transparent conductive thin films were prepared by RF sputtering deposition of ZnO target and DC sputtering deposition of Cu target on n-type （001） Si and glass substrates at room temperature. The mor- phology, structure, optical, and electrical properties of the multilayer films were characterized by field emission scanning electron microscope （FESEM）, X-ray diffraction （XRD）, UV/Vis spectrophotometer, and Hall effect mea- surement system. The influence of Cu layer thickness and the oxygen pressure in sputtering atmosphere on the film properties were studied. ZnO/Cu/ZnO transparent conduc- tive film fabricated in pure Ar atmosphere with 10 nm Cu layer thickness has the best performance： resistivity of 2.3 × 10^-4 Ω.cm, carrier concentration of 6.44 × 10^16 cm-2, mobility of 4.51 cm2.（V.s）-1, and acceptable aver- age transmittance of 80 % in the visible range. The trans- mittance and conductivity of the films fabricated with oxygen are lower than those of the films fabricated without oxygen, which indicates that oxygen atmosphere does not improve the optical and electrical properties of ZnO/Cu/ ZnO films.

A Novel Method of Fabricating Flexible Transparent Conductive Large Area Graphene Film

We fabricate flexible conductive and transparent graphene films on position-emission-tomography substrates and prepare large area graphene films by graphite oxide sheets with the new technical process. The multi-layer graphene oxide sheets can be chemically reduced by HNO3 and HI to form a highly conductive graphene film on a substrate at lower temperature. The reduced graphene oxide sheets show a high conductivity sheet with resistance of 476Ω/sq and transmittance of 76% at 550nm （6 layers）. The technique used to produce the transparent conductive graphene thin film is facile, inexpensive, and can be tunable for a large area production applied for electronics or touch screens.

Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO_2 Films Deposited by APCVD

Transparent conducting F-doped texture SnO2 films with resistivity as low as 5× 10-4 Ω ·cm,with carrier concentrations between 3.5 × 1020 and 7× 1020 cm-3 and Hall mobilities from 15.7 to 20.1 cm2/(V/s) have been prepared by atmosphere pressure chemical vapour deposition (APCVD). These polycrystalline films possess a variable preferred orientation, the polycrystallite sizes and orientations vary with substrate temperature. The substrate temperature and fluorine flow rate dependence of conductivity, Hall mobility and carrier conentration fOr the resultingfilms have been obtained. The temperature dependence of the mobiity and carrier concentrationhave been measured over a temperature range 16～400 K. A systematically theoretical analysis on scattering mechanisms for the highly conductive SnO2 films has been given. Both theoretical analysis and experimental results indicate that for these degenerate, polycrystalline SnO2 ：F films in the low temperature range (below 100 K), ionized impurity scattering is main scattering mechanism. However, when the temperature is higher than 100 K, the lattice vibration scattering becomes dominant. The grain boundary scattering makes a small contribution to limit the mobility of the films.

Preparation and Characterization of Transparent Conductive Zinc Doped Tin Oxide Thin Films Prepared by Radio-frequency Magnetron Sputtering

High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.

Effect of Oxygen Concentration and Annealing Theatment on the Optical Properties of the Transparent Conductive CdIn_2O_4 Thin Films

Transparent conductive cadmium indium oxide films (CdIn2O4) were prepared by r.f. reactive sputtering from Cd-In alloy targets under an Ar-O2 atmosphere. Electrical conductivity of the order of 105Ω-1.m-1 and the optical transmission as high as 94% are easily attained by postdeposition annealing treatment. The effects of oxygen concentration in the reactive gas mixture and post-deposition annealing treatment on the optical transmittance as well as optical parameters, such as refractive index (n), extinction coefficient (k), real part (ε') and imaginary part (ε') of the dielectric constant, were studied in the visible and near-infrared region. The highfrequency dielectric constant ε∞ the plasma frequency ωP, and the conduction band effective mass mc of different samples were also investigated

Characteristics Improvement of PEDOT:PSS Transparent Conductive Film Prepared by Ink-Jet Printing

Recently, a high-performance and low-priced transparent conductive film has been expected to be developed because flexible devices produced using organic materials have been actively studied. An indium tin oxide (ITO) thin film, which has been generally used as a material for a transparent conductive film, has problems, such as fragility to bending stress and depletion of the resource. The present study used poly(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), an organic electroconductive material, and examined the improvement in the resistance value and visible light transmittance of a transparent conductive film produced using the ink-jet method. In previous studies, we reported that, to improve the resistance value and visible light transmittance of a thin film, it was effective to clean the film substrate with ultraviolet/ozone (UV/O3) treatment, anneal the film after it was deposited on the substance, and dip the annealed film into a polar solvent. Focusing on the thin film processing between printing operations, the present study improved resistance value and visible light transmittance by examining both the application methods of a polar solvent and the annealing time between printing operations. As a result, the resistance value and visible light transmittance of a PEDOT:PSS thin film were 390.4 Ω and 86.6%, respectively. This film was obtained by applying a polar solvent and performing annealing for 30 min between printing operations. The printing was performed three times.

THE BAND STRUCTURE AND WORK FUNCTION OF TRANSPARENT CONDUCTING ALUMINUM AND MANGANESE CO-DOPED ZINC OXIDE FILMS

Al and Mn co-doped-ZnO films have been prepared at room temperature by DC reacti ve magnetron sputtering technique. The optical absorption coefficient, apparent and fundamental band gap, and work function of the films have been investigated using optical spectroscopy, band structure analyses and ultraviolet photoelectro n spectroscopy (UPS). ZnO films have direct allowed transition band structure, w hich has been confirmed by the character of the optical absorption coefficient. The apparent band gap has been found directly proportional to N2/3, showing that the effect of Burstein-Moss shift on the band gap variations dominates over the many-body effect. With only standard cleaning protocols, the work function of ZnO: (Al, Mn) and ZnO: Al films have been measured to be 4.26 and 4.21eV, respec tively. The incorporation of Mn element into the matrix of ZnO, as a relatively deep donor, can remove some electrons from the conduction band and deplete the d ensity of occupied states at the Fermi energy, which causes a loss in measured p hotoemission intensity and an increase in the surface work function. Based on th e band gap and work function results, the energy band diagram of the ZnO: (Al, M n) film near its surface is also given.

A Transparent Thin Film with Hexagonal Mesostructure Containing Rhodamine 6G

A transparent thin film was prepared by depositing the sol-gel mixture for the synthesis of MCM-41 mesoporous molecular sieve doped with rhodamine 6G (R6G) dye on glass substrates. The film of silica-surfactant-R6G materials, which was identified to possess hexagonally ordered mesostructure, was composed of nanocrystallites about 35 nm in diameter and 1-10 mm in thickness. Cleanness of the substrates, concentration of the sol-gel mixture and rate of evaporation of the solvent were the key factors affecting transparency and homogeneity of the film. Moreover, optical change and lack in dye aggregation were observed to the R6G-functionalized MCM-41 thin film in contrast with that in ethanol solution.

Optical and electrical properties of BaSnO_(3) and In_2O_(3) mixed transparent conductive films deposited by filtered cathodic vacuum arc technique at room temperature

For the crystalline temperature of BaSnO_(3)(BTO)was above 650℃,the transparent conductive BTO-based films were always deposited above this temperature on epitaxy substrates by pulsed laser deposition or molecular beam epitaxy till now which limited there application in low temperature device process.In the article,the microstructure,optical and electrical of BTO and In_(2)O_(3) mixed transparent conductive BaInSnO_(x)(BITO)film deposited by filtered cathodic vacuum arc technique(FCVA)on glass substrate at room temperature were firstly reported.The BITO film with thickness of 300 nm had mainly In_(2)O_(3) polycrystalline phase,and minor polycrystalline BTO phase with(001),(011),(111),(002),(222)crystal faces which were first deposited at room temperature on amorphous glass.The transmittance was 70%–80%in the visible light region with linear refractive index of 1.94 and extinction coefficient of 0.004 at 550-nm wavelength.The basic optical properties included the real and imaginary parts,high frequency dielectric constants,the absorption coefficient,the Urbach energy,the indirect and direct band gaps,the oscillator and dispersion energies,the static refractive index and dielectric constant,the average oscillator wavelength,oscillator length strength,the linear and the third-order nonlinear optical susceptibilities,and the nonlinear refractive index were all calculated.The film was the n-type conductor with sheet resistance of 704.7Ω/□,resistivity of 0.02Ω⋅cm,mobility of 18.9 cm2/V⋅s,and carrier electron concentration of 1.6×10^(19) cm^(−3) at room temperature.The results suggested that the BITO film deposited by FCVA had potential application in transparent conductive films-based low temperature device process.

Fabrication of High-Haze Flexible Transparent Conductive PMMA Films Embedded with Silver Nanowires

High-haze flexible transparent conductive polymethyl methacrylate （PMMA） films embedded with silver nanowires （AgNWs） are fabricated by a low-cost and simple process. The volatilization rate of the solvent in PMMA solution affects the surface microstructures and morphologies, which results in different haze factors of the composite films. The areal mass density of AgNW shows a significant influence on the optical and electrical properties of composite films. The AgNW/PMMA transparent conductive films with the sheet resistance of 5.5Ω sq ^-1 exhibit an excellent performance with a high haze factor of 81.0% at 550？nm.

Effects of Substrate Temperature on Properties of Transparent Conductive Ta-Doped TiO_2 Films Deposited by Radio-Frequency Magnetron Sputtering

Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350℃ on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region（400-800 nm） of all films is more than 73%.The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150℃ exhibits a lowest resistivity of 7.7 × 10^-4Ω·cm with the highest carrier density of 1.1×10^21 cm^-3 and the Hall mobility of 7.4 cm^2·V^-1s^-1.

Fabrication and properties of ZAO powder,sputtering target materials and the related films

Aluminum-doped zinc oxide （ZnO：Al）, abbreviated as ZAO, is a novel and widely used transparent conductive material. The ZAO powder was synthesized by chemical coprecipitation. The ZAO ceramic sputtering target materials were fabricated by sintering in air, and ZAO transparent conductive films were prepared by RF magnetron sputtering on glass substrates. XRD proved that such films had an orientation of （002） crystal panel paralleled to the surface of the glass substrate. The average transmittance of the films in the visible region exceeded 80%.