ITO-coated Glass Substrates Research Articles

High infrared reflectance modulation in VO2 films synthesized on glass and ITO coated glass substrates using atmospheric oxidation of vanadium

Vanadium Dioxide (VO2) is a strongly correlated material, which exhibits insulator to metal transition at ~68 C along with large resistivity and infrared optical reflectance modulation. In this work, we use atmospheric pressure thermal oxidation of Vanadium to synthesize VO2 films on glass and ITO coated glass substrates. With the optimized short oxidation durations of 2 min and 4 min, the synthesized VO2 film shows high optical reflectance switching in long-wavelength infrared on glass substrates and mid-wavelength infrared on ITO coated glass substrates, respectively. Peak reflectance switching values of ~76% and ~79% are obtained on the respective substrates, which are among the highest reported values. Using the reflectance data, we extract VO2 complex refractive index in infrared wavelengths, in both the insulating and metallic phases. The extracted refractive index shows good agreement with VO2 synthesized using other methods. This demonstration of high optical reflectance switching in VO2 thin films, grown on low cost glass and ITO coated glass substrates, using a simple low thermal budget process will aid in enhancing VO2 applications in the optical domain.

Detailed transmittance analysis of high-performance SnO2-doped WO3 thin films in UV–Vis region for electrochromic devices

WO3 is a popular electrochromic device and therefore it has extensively used for the electrochromic (EC) devices such as display and smart window applications. In this study, SnO2-doped WO3 thin films have been deposited to obtain high-performance EC device and detailed transmittance analysis was determined. At the end of this study, general coloring–bleaching mechanism for SnO2-doped WO3 active layer is presented. Li ion intercalation/de-intercalation is seen in Nyquist graph for the SnO2-doped WO3 thin film deposited onto ITO coated glass substrate. All tests were done in 80 s in coloring and bleaching of the SnO2-doped WO3 layer. Reversibility values of the EC devices mounted in this study were calculated to be 79 and 90% for the device with ITO or FTO conductive layers, respectively. According to the morphological analysis, grain distribution on the surfaces defined as to be perfect. Thanks to Raman analyses, the SnO2–WO3 phases are seen. Finally, the EC devices have been working in the UV–Vis region. As a result, to obtain the high-performance EC device, SnO2-doped WO3 active layer is a good choice. TVA method is also proper technology to device manufacturing.

Radiation induced photocurrent in the active volume of P3HT/PCBM BHJ photodiodes

Abstract The purpose of this work is to fabricate and characterize the response of a P3HT/PCBM bulk heterojunction organic photodiode to photon beams with respect to dose rate, total dose, and energy. A bulk heterojunction (BHJ) organic photodiode was fabricated by spin coating a blend of P3HT and PCBM onto an ITO-coated glass substrate and then depositing aluminum top contacts. Control devices were made by spin coating polystyrene instead of the P3HT/PCBM layer. The devices were irradiated with a 6 MV photon beam with dose rates of 100–600 cGy/min. Energy dependence was measured for energies of 100, 180, and 300 kVp and 6 and 10 MV. Photocurrent in the BHJ was calculated by subtracting the average current measured using the four PS devices from that measured with each of the four BHJ diodes to correct for current collected by the electrodes and the wires/connectors. The sensitivities of the four BHJ devices were within the range of 3.7–4.3 pC/cGy. The range of values is mostly due to inter-device variation and not due to variation between readings on the ITO and Al electrodes of a single device. The diodes exhibit an energy dependence with more than 4 times the response at 100 kVp than at 6 MV. The direction and magnitudes of the measured currents after correction for the electrode/lead currents were consistent with photocurrent. The photocurrents increased linearly with dose rate indicating they could be suitable in radiation sensing applications.

DC sputter deposited TiO2 thin film on ITO/glass substrate for perovskite based solar cell application

A compact TiO2 (c-TiO2) thin film, which acts as electron transport layer (ETL) in perovskite type solar cell is deposited onto ITO coated glass substrate using DC sputtering at room temperature followed by post annealing treatment at 450 °C and 500 °C for 2 h. The films are deposited for 90 min. Ellipsometry studies showed that the thickness of deposited sample is about 57 nm. XRD pattern of TiO2 coated ITO bilayer revealed the anatase phase of TiO2 along with polycrystalline nature of cubic phase In2O3. Optical transmittance of TiO2/ITO bilayer exhibited an average of 80% transmission of light. Energy band gap of the TiO2 layer is found to be 3.2 eV. SEM images showed smooth, uniform and defect free thin film of TiO2 on ITO substrate. Band gap of deposited mesoporous TiO2 (m-TiO2), CH3NH3SnI3 and CuI thin layers are found to be 3.2 eV, 1.5 eV and 3.1 eV, respectively. Sn based perovskite solar cell is fabricated with a device structure of glass/ITO/c-TiO2/m-TiO2/CH3NH3SnI3/CuI/Au. Sn based perovskite solar cell is a promising candidate to overcome the toxic and high cost solar cells.

Effects of lattice mismatches in In2O3/substrate structures on the structural, morphological and electrical properties of In2O3 films

Indium oxide thin films were deposited by ultrasonic spray technique on ITO coated glass and single crystalline Si (400) substrates at 400 °C. Lattice mismatch effect on the crystalline structure, surface morphology and electrical properties of these samples is then studied. X-ray diffraction (XRD) and Raman spectroscopy patterns suggest that the films deposited on ITO coated glass substrate are polycrystalline in nature having a cubic crystal structure with a preferred grain orientation along the (222) plane. However, films deposited on Si wafer substrate, exhibit randomly oriented growth. The crystallite size varies from 18 to 66.5 nm. AFM topographical images revealed that the In2O3/ITO films follow 2D or layer-by-layer-growth. But in the case of In2O3/Si films, 3D or island growth becomes dominant. The In2O3/ITO films is found to exhibit a higher value of conductivity (σ = 5 × 102 Ω−1 cm−1) than the In2O3/Si films, and the low value of the RMS roughness (9.83 nm).

Significant effect on annealing temperature and enhancement on structural, optical and electrical properties of zinc oxide nanowires

This paper focused on the growth of zinc oxide nanowires on unannealed and annealed indium tin oxide-coated-coated glass substrates on the structural, optical, and electrical properties towards surface acoustic wave (SAW) piezoelectric nanodevices. Zinc oxide nanowires (ZnO NWs) were grown onto Indium Tin Oxide (ITO)-coated glass substrates by a chemical bath deposition method. The growth of ZnO NWs carried onto unannealed and annealed Indium Tin Oxide-coated glass substrates. Substrates were annealed at 400 °C for 90 min at ambient using a horizontal furnace. This work also focused on the effect of annealing condition of ITO-coated glass substrate on nanowires morphology, crystal phase, optical band gap, and electrical properties. Substrate annealing was found to have a significant effect on the nanowires dimension. The nanowire's morphology was obtained by FESEM which the average diameter and length found on unannealed ITO-coated glass substrate were 674.18 ± 26.75 nm and 3.107 ± 0.446 μm. However, the nanowire's average diameter and length on annealed ITO-coated glass substrate were 393.50 ± 27.02 nm and 3.175 ± 0.321 μm. XRD analysis confirmed that ZnO nanowires on substrates with both conditions were able to promote the growth of crystal structure with crystal plane orientation of (1 0 1) and (1 0 0) belongs to hexagonal wurtzite structure. The near-band-edge (NBE) emission of ZnO nanowires obtained by using Photoluminescence which grown on unannealed and annealed ITO-coated glass substrates were observed at 380 nm (3.20 eV) and 384 nm (3.23 eV). FTIR analysis showed that ZnO absorption bands in the region between 450 and 500 cm−1 had arisen from interatomic vibrations due to the stretching of the ZnO bond. The resistivity of ZnO nanowires obtained by using the four-point probe method on unannealed and annealed substrates was found to be 2.0675 × 10−7 Ω cm and 2.0494 × 10−7 Ω cm.

Investigation of TiO2 thin films as a cathodic material for electrochromic display devices

Titanium dioxide is a preferred material in many fields of applications and is also used as one of best electrochromic display (ECD) candidates due to its chemical stability. Electrochromic devices are innovative, low-cost and low energy consumption for using as displays. In this work, electrochromic, morphological, structural, and some optical properties of tandem structures were comprehensively investigated. The mean thicknesses of the samples were measured as 86 and 120 nm on ITO- and FTO-coated glass substrates, respectively. The chronoamperometry test was performed to determine some electrochromic properties of the ECD. It was observed that the amounts of ions intercalated/de-intercalated from the coated TiO2 layer were almost equal to each other. According to the chronocoulometric analysis, the superior reversibility and coloration efficiency of the assembled ECD were found to be 83% and 26 cm2/C, respectively, onto ITO substrates. Higher reversibility is revealed in thinner films, which is consistent with the obtained thickness results. In a similar manner, highest coloration efficiency obtained for our ECD has demonstrated good contact between the TiO2-deposited layer and the ITO-coated glass substrate. Also, the highest porosity was reached by taking the highest coloration efficiency value into account. Moreover, coloration efficiencies and ΔT ratios are changed due to the interlayer transparent conductive oxide layers. Raman spectroscopy measurement reveals the anatase phase of TiO2 films on both substrates. Another important finding is related to the defect structures of the TiO2 phase. TiO2, TiO3 and TiO4 mixed phases show the lower coloration efficiency according to the TiO2 phase, for the first time. TiO3 and TiO4 phases were grown by using the FTO-coated glass substrate. Comparing results with reports has shown that our investigated design and technology for ECD applications are good candidates for such applications.

Understanding the growth mechanism of single vapor bubble on a hydrophobic surface: Experiments under nucleate pool boiling regime

Growth and departure characteristics of single vapor bubble on hydrophobic surfaces have been investigated under saturated bulk conditions. Nucleate pool boiling experiments, with water as the working fluid, have been carried out on two sets of hydrophobic surfaces; (1) black painted ITO-coated glass substrate, and (2) ITO-coated sapphire substrate subjected to two different levels of constant heat flux conditions. High speed camera was employed to characterize the bubble dynamics. In conjunction with the high speed camera, an IR thermal imaging camera was used to simultaneously map the spatio-temporal temperature distribution of the substrate underneath the growing vapor bubble. Compared to the black paint coated glass substrate, significantly higher transmissivity of sapphire substrate in the mid-IR spectral range ensured the authenticity of the spatio-temporal accuracy of temperature measurements of the bubble nucleation site using the employed IR camera. Results on the bubble growth clearly showed that, irrespective of the substrate employed, the bubble exhibits almost zero waiting time, leaving a small residue of vapor on the substrate after the bubble departure, which further acts as a nucleus for the next bubble. Moreover, the bubble growth process was observed to be extremely slow. The IR camera-based temperature field of the hydrophobic substrates revealed that the presence of vapor bubble does change the local temperature of the substrate underneath the vapor bubble. However, it was observed that the temperature field of the nucleation site does not change with bubble growth and its departure, which, in turn, indicated towards the possibility that the microlayer ceases to exist underneath the vapor bubble. This is in contrast to the microlayer evaporation-driven growth of single vapor bubble on a hydrophilic substrate. Based on these direct experimental observations, plausible bubble growth mechanism(s) on the given hydrophobic surfaces have been predicted and discussed.

Synthesis and characterization of poly(EGDMA-co-VPCA)/SWCNT composite films by surface polymerization method

Poly (EGDMA–co-VPCA)/SWCNT composite materials were produced on ITO coated glass substrates by surface polymerization method. Physical facilities of the deposits were studied by some techniques and approximation methods such as FTIR, SEM, EDS, MS and EIS. FTIR analyses confirm the formation of poly (EGDMA–co-VPCA)/SWCNT composite film. SEM studies show that the SWCNTs are embedded into the EGDMA-co-VPCA polymer. Semiconducting parameters, such as acceptor density, donor density, flat band voltage, positions of the valence and conduction energy band edge of the poly (EGDMA-co-VPCA)/SWCNT film are obtained by use of the Mott-Schottky and optical measurements. Mott-Schottky curves show that poly (EGDMA-co-VPCA)/SWCNT composite material exhibits both n-type and p-type conductivity depending on the applied potential. The EIS data were collected from poly (EGDMA-co-VPCA)/SWCNT/ITO/electrolyte system at a frequency range between 0.01 Hz and 300 kHz. Therefore, an equivalent electronic circuit model was fitted to the EIS data or Nyquist data. After the determination of the electronic circuit elements, charge transfer properties between electrolyte and composite polymer are also discussed from the standpoint of solution resistance, charge transfer resistance and constant phase element.

High responsivity ZnO based p–n homojunction UV-photodetector with series Schottky barrier

In the present article, we proposed a p–n homojunction photodetector with a series Schottky barrier and a high value of responsivity in the ultraviolet region. The thin-film photodetector makes use of a junction between an RF-sputtered n-type ZnO nanostructure and a p-type copper doped ZnO (CZO) thin film derived through the spin coating process on an ITO coated glass substrate. Palladium metal contacts have been deposited to form the Schottky barrier in series with the p–n homojunction. The device has been simulated, fabricated, and tested only after ensuring the stability of the p-type CZO thin film. The measured I–V characteristics of the fabricated photodetector under illuminated and dark conditions showed excellent UV response and good rectification properties. The device exhibits a peak responsivity of 13.2 A W−1 for a reverse biasing voltage of 3 V. This value is much higher than the values reported by others for a ZnO based photodetector.

Two-dimensional BN-doped ZnO thin-film deposition by a thermionic vacuum arc system

Graphene is an interesting two-dimensional dopant for the electronic, electrochemical, and optoelectronic devices due to its high electron mobility, high electrical, and thermal conductivity, and high optical transparency. Another graphene-like material is boron nitride (BN). h-BN shares similar lattice structure with graphene and many physical properties except large bandgap. In this study, optical, morphological, and structural properties of the two-dimensional BN-doped ZnO thin films have been investigated with various techniques such as UV–Vis spectroscopy, field emission scanning electron microscopy, atomic force microscopy, and Raman spectroscopy. Two-dimensional BN-doped ZnO thin films were produced onto glass, indium tin oxide-coated glass, and fluorine tin oxide-coated glass using by a Thermionic Vacuum Arc (TVA) deposition technique. The results show that the substrate effect causes the different growth mechanisms for the two-dimensional BN-doped ZnO thin films. It is found that bandgap of ZnO changed drastically and bandgaps of the deposited thin films were found to be 3.96 eV, 3.97 eV, 4.05 eV for two-dimensional BN-doped ZnO thin films deposited onto glass, ITO-coated glass, and FTO-coated glass substrates, respectively. According to the Raman spectra, BN crystal orientations are in hexagonal form in ZnO crystal.

Ion-Conducting Dynamic Solid Polymer Electrolyte Adhesives.

Cross-linked polymer electrolytes containing structurally dynamic disulfide bonds have been synthesized to investigate their combined ion transport and adhesive properties. Dynamic network polymers of varying cross-link densities are synthesized via thiol oxidation of a bisthiol monomer, 2,2'-(ethylenedioxy)diethanethiol, and tetrathiol cross-linker, pentaerythritol tetrakis(3-mercaptopropionate). At optimal loading of lithium bis(trifluoromethane-sulfonyl-imide) (LiTFSI) salt, the ionic conductivities (σ) at 90 °C are about 1 × 10-4 and 1 × 10-5 S/cm at the lowest and highest cross-linking, respectively. Notably, in comparison to the equivalent nondynamic network, the dynamic network shows a positive deviation in σ above 90 °C, which suggests the enhancement of ion transport occurs from the difference in structural relaxation on account of the dissociation of disulfide bonds. Lap shear adhesion and conductivity tests on ITO-coated glass substrates reveal the dynamic network exhibits a higher adhesive shear strength of 0.2 MPa (vs 0.03 MPa for the nondynamic network) and higher σ after the application of external stimulus (UV light or heat). The adhesive strength and σ are stable over multiple debonding/rebonding cycles and, thus, demonstrating the utility of these structurally dynamic networks as solid polymer electrolyte adhesives.

MnO2 and TiO2 based Nanocomposites for Macroscopic and Individual Nanodevices in Sensing, Energy Storage and Photocatalysis Applications

The present nanotechnological trend is promising for the devices based on nanocomposites. We focus on three application areas, biosensing, energy storage and photocatalyst. A newer frontier trend is related to individual nano-devices based on individual nano-objects giving the exciting advantages. In the present work, the MnO2 and TiO2 nanocomposites were developed by simple and economical means. The MnO2 and Cu/MnO2 were potentiodynamically deposited on stainless steel sheets and ITO coated glass substrates for energy storage and sensing applications. The electrochemically anodized TiO2 nanotubes and Ag nanoparticles decorated TiO2 nanotubes were fabricated on Ti base for photocatalysis. The MnO2 film electrode, Cu/MnO2 film electrode, Ag/TiO2 nanotubes were preliminarily demonstrated as macroscopic devices in capacitors, glucose sensors and photocatalysis water treatments. The specific capacitance of MnO2 film electrode is as high as 135 Fg−1and the Cu/MnO2 sensor has the low detection limit of 0.986. For the water purification, the photodegradation efficiency of Ag/TiO2 nanotubes is as high as 95% under UV irradiation.

Substrate effect on structural and electrochemical properties of LiFePO4 thin films grown by pulsed laser deposition

LiFePO4 thin films are grown by pulsed laser deposition technique in relation to deposition parameters. Different characterizations such as XRD, SEM, Raman, and electrochemical studies are undertaken on the prepared samples. Structural phase of the deposited thin film expresses the orthorhombic Pnma olivine. LiFePO4 thin films grown on Pyrex glass substrate have harsh surface with a few dispatches of grains, whereas the thin films deposited on ITO-coated glass substrate have demonstrated exceptionally fine and uniform particles without dispatches of grains. Raman peaks are situated at 1237.7 and 1416 cm−1. From the conductivity studies, the conductivity has been raised for the Pyrex glass up to 1.1 × 10−4 S cm−1 at 373 K, whereas in case of ITO-coated glass, the conductivity has been enhanced up to 1.6 × 10−4 S cm−1 at 373 K. The transmission spectra change CC from obscurity state to free state from 15 to 83% at around 39 cm2 C−1. CV of LiFePO4 thin film on ITO-coated glass substrate has exhibited the anodic and cathodic peaks at 3.2 and 3.19 V. These outcomes demonstrate that the determination of a suitable substrate is significant for creating the film terminal with the high rate limit, particularly in considering the utilization of microbatteries.

Channel integrated optoelectronic tweezer chip for microfluidic particle manipulation

Light patterned electrical fields have been widely used for the manipulation of microparticles, from cells to microscopic electronic components. In this work, we explore a novel electromechanical phenomenon for particle focusing and sorting where the electrical field patterns are shaped by a combination of the light patterned photoconductor and the channel geometry. This effect results from the combination of particle polarisation described by the Clausius–Mossotti relation and the engineering of large electric gradients produced by choosing the channels height to suit the size of the particles being manipulated. The matched geometry increases the distortion of the field created by a combination of the illuminated photoconductor and the particles themselves and hence the non-uniformity of the field they experience. We demonstrate a new channel integration strategy which allows the creation of precisely defined channel structures in the OET device. By defining channels in photoresist sandwiched between upper and lower ITO coated glass substrates we produce robust channels of well controlled height tailored to the particle. Uniquely, the top substrate is attached before photolithographically defining the channels. We demonstrate versatile control using this effect with dynamically reconfigurable light patterns allowing the retention against flow, focusing and sorting of micro particles within the channels. Contrary to traditional designs, this channel integrated device allows patterned micro channels to be used in conjunction with conductive top and bottom electrodes producing optimal conditions for the dielectrophoretic manipulation as demonstrated by the rapid flow (up to 5 mm s−1) in which the particles can be focused.

ZnO nanostructures grown on ITO coated glass substrate by hybrid microwave-assisted hydrothermal method

Over the last decades, zinc oxide nanostructures (NSs) have been studied due to outstanding chemical and physical properties, able to serve a plethora of applications. The growth of NSs on different substrates coated with ITO film allow their direct implementation in various micro-/nano-devices. The microwave-assisted hydrothermal method is a new hybrid approach used for synthesis of oxide NSs due to unique advantages in energy efficiency/high reaction rate and possibility of obtaining different morphologies with size and shape-controlled, which are relevant for some applications.In this paper, we present a simple one step synthesis of ZnO 1D and 2D NSs with homogeneous distribution and orientation perpendicular to substrates covered with ITO film, using a microwave-assisted hydrothermal method. The effect of seed layer treatment on the structure, morphology and optical properties of the obtained NSs have been investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), UV/VIS/NIR and photoluminescence spectroscopy. The obtained ZnO NSs with 1D and 2D morphologies show high visible transmittance between 80–90 % and band gap energy values between 3.27 and 3.22 eV. The I-V curves and photoluminescence spectra indicate good ohmic contacts on both sides (ITO and Au-top electrodes) and highlight the effect of the thermal treatment of seed layer on the photoluminescence emission and electrical conductivity of the obtained NSs.

Development and characterization of photodiode from p-Cu2CdSnS4/n-Bi2S3 heterojunction

Here we investigated the photo response behaviour of p-Cu2CdSnS4 (p-CCTS)/n-Bi2S3 heterojunction photodiode. The solution processed CCTS films without any high temperature sulfurization demonstrated the photo response behaviour, suggesting the material is well suited for low temperature processed photovoltaic applications. A CCTS film was deposited on an ITO coated glass substrate using simple sol-gel based spin coating method. Current–voltage (I–V) characteristic of the p-CCTS/n-Bi2S3 heterojunction photodiode showed a good rectifying behaviour indicating better junction formation between CCTS and Bi2S3 layers. The obtained photocurrent is 4 times higher than that of the dark current. The I–V curves are asymmetric with respect to voltages and the photocurrent in the positive bias region is considerably higher than the corresponding values in the negative bias region. With these results, it is concluded that the CdS material in traditional thin film PV devices can be replaced with Bi2S3 for better transportation of charge carriers in the PN-junction.

Influence of Al doping on random lasing in ZnO nanorods

Random lasing was demonstrated from aluminum doped ZnO nanorods fabricated on ITO coated glass substrates using simple chemical deposition technique. Different Aluminum (Al) doping parameters were explored in an attempt to realize low threshold ZnO random lasers. Results confirm threshold was strongly dependent on doping concentration and suggestive of resonant coupling with Al in lowering the threshold by 2 orders of magnitude when compared to undoped ZnO nanorods. Lowest threshold was obtained from ZnO nanorods doped with 10 mM of aluminum, suggesting best doping concentration for ZnO random lasers formed by nanorod array. Results further indicate possibility of controlling random lasing properties by adjusting the doping concentration.

CuO/Cu core/shell nanostructured photoconductive devices by hot water treatment and high pressure sputtering techniques

This work demonstrates the fabrication of simple photoconductive devices based on CuO/Cu core/shell nanostructured heterojunction that performs notable photocurrent response. Copper oxide (CuO) nanoleaf structures (NLs) have been successfully grown on ITO-coated glass substrate via a simple hot water treatment (HWT) method. A conformal Cu shell was fabricated by high pressure sputtered (HIPS) deposition technique on the CuO nanoleaves to produce NLs-core/metal shell photoconductive devices. For comparison, CuO thin film (TF) was prepared by the thermal oxidation method to manufacture the conventional planar thin film devices. Results showed that the HWT method resulted in the formation of dense 3D CuO nanoleaves on ITO/glass substrate with a high surface area. CuO NLs showed higher optical absorption than CuO TF in the ultraviolet and visible spectrum. Further, the optical band gaps of CuO NLs and TF samples have been estimated from Touc’s plot to be 1.45 ± 0.10 eV and 1.63 ± 0.20 eV, respectively. Current density–voltage measurements’ result revealed that core/shell devices have superior photocurrent response compared to TF devices. The average photocurrent density at zero-bias for the NLs devices was 23.5 ± 2.0 μA cm−2 and for TF devices was 6.7 ± 1.0 μA cm−2. Besides, NLs core/shell photoconductive devices exhibit a remarkable increase in photocurrent response values with increasing bias voltage compared to the increased values in TF devices. The results demonstrate that the devices based on HWT-NLs-core/HIPS-shell design showed a significant enhancement on the photoconductivity response compared with the conventional TF design. The performance enhancement can be attributed to improving light trapping, photocarriers generation-recombination times and carrier collection by introducing an alternative radial interface in core/shell design. Also, HWT CuO NLs geometry feature with the high surface area has worked to enhance light absorption that enables the design of high efficiency, functional and commercial photoconductive detectors.

Efficient solvothermal reduction of coarse-scale graphene oxide

Solvothermal reduction of graphene oxide performed up to a sp2/sp3 ratio of 20 was demonstrated. The presence of chemical and structural defects was minimized by varying the treatment conditions and reduction agents to reduce their impact on electronic and optical properties. Using the interphase deposition technique both graphene oxide and reduced graphene oxide films were transferred onto ITO-coated glass substrates or SITAL for further analysis. The analysis of the electric characteristics of the reduced graphene oxide films showed high sheet resistance originated from grain boundary resistance. The optical transmittance of the films reached 30% for the most uniform coatings.