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Electrochromic devices (ECDs) have been drawing great attention due to their high color contrast, low power consumption, and memory effect, and can be used in smart windows, automatic dimming mirrors, and information display devices. As with other electronic devices such as LEDs (light emitting diodes), solar cells, and transistors, the mechanical flexibility of ECDs is one of the most important issue for their potential applications. In this paper, we report on flexible ECDs (f-ECDs) fabricated using an all-in-one EC gel, which is a mixture of electrolyte and EC material. The f-ECDs are compared with rigid ECDs (r-ECDs) on ITO glass substrate in terms of color contrast, coloration efficiency, and switching speed. It is confirmed that the f-ECDs embedding all-in-one gel show strong blue absorption and have competitive EC performance. Repetitive bending tests show a degradation of electrochromic performance, which must be improved using an optimized device fabrication process.

Carbazoles are excellent chromophores for electrochromic (EC) applications owing to their exceptional oxidation properties. Herein, we synthesized a donor-acceptor-type small molecule semiconductor, named LGC-D023, containing carbazole as a core donor, diketopyrrolopyrrole as a weak-acceptor π-linker, and 3-octylrhodanine as an electron-acceptor end-unit; and characterized its optical, thermal, and EC properties. LGC-D023 exhibited good organic solvent solubility, as well as distinct melting and crystallization transitions above 200 °C. Spectroelectrochemical spectra showed blue (L*: 88.28, a*: −6.56, b*: −1.29)-to-red (L*: 93.61, a*: 2.94, b*: −0.75) color switching with a high optical contrast (35.3%), fast response time (>0.3 s), and desirable coloration efficiency (91.9 cm2/C). These results confirmed that this donor-acceptor small molecule could be a new promising candidate for an EC material.

We synthesize a quinoxaline-based novel conjugated donor–acceptor random copolymer containing benzodithiophene and 2,5-difluorophenylenedithiophene units as electron donors (coded r-PQ) and investigate the electrochromic properties of the material. Despite its high molecular weight, r-PQ is highly soluble in organic solvents owing to the side chain of alkoxy at the meta-position of the phenyl ring. The r-PQ film exhibits excellent redox-promoted blue to transmissive-state color switching with high coloration efficiency (>250 cm2/C) and a fast response time (

We report on stretchable electrochromic films of poly(3-hexylthiophene) (P3HT) fabricated on silver nanowire (AgNW) electrodes. AgNWs electrodes are prepared on polydimethylsiloxane (PDMS) substrates using a spray coater for stretchable electrochromic applications. On top of the AgNW electrode, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is introduced to ensure a stable resistance over the electrode under broad strain range by effectively suppressing the protrusion of AgNWs from PDMS. This bilayer electrode exhibits a high performance as a stretchable substrate in terms of sheet resistance increment by a factor of 1.6, tensile strain change to 40%, and stretching cycles to 100 cycles. Furthermore, P3HT film spin-coated on the bilayer electrode shows a stable electrochromic coloration within an applied voltage, with a color contrast of 28.6%, response time of 4-5 sec, and a coloration efficiency of 91.0 cm2/C. These findings indicate that AgNWs/PEDOT:PSS bilayer on PDMS substrate electrode is highly suitable for transparent and stretchable electrochromic devices.

Despite the great potential presented by small molecular compounds, small molecule electrochromic materials receive less attention than polymer-based electrochromic materials. In this work, the synthesis of a novel π-conjugated small molecular electrochromic material, LGC-D055, is described. This material contains dithiophene-phenylene with a bulky trihexylsilyloxy side chain at its core, diketopyrrolopyrrole with a siloxane-terminated hybrid alkyl chain as the linker, and ethylrhodanine as the end group. LGC-D055 presents excellent solubility in organic solvents due to the presence of these bulky side chains. The spin-coated films of LGC-D055 exhibit blue/transparent electrochromism with a fast switching speed of 0.4 s and high coloration efficiency over 300 cm2/C.

Herein, we report the effects of applied voltage on the electrochromic (EC) stability of poly(3-hexylthiophene) (P3HT) films during EC reactions. The transmittance difference and cycling stability of these films were monitored to optimize the oxidation voltage, and their chemical compositions were analyzed by X-ray photoelectron spectroscopy after long-term electrochemical cycling. High oxidation voltages increased the color contrast of P3HT films but decreased their cycling stability due to facilitating chemical degradation. Furthermore, at an optimized oxidation voltage, the retention time during potential pulsing was adjusted utilizing the optical memory of P3HT, revealing that the decreased voltage application time reduced power consumption by 9.6% and enhanced EC stability without loss of color contrast.

Electrodeposition is a simple and effective method for the synthesis of disordered hydrated vanadium pentoxide (V2O5·nH2O). For the synthesis of energy storage electrodes with high power performance, electrodeposition of hydrated V2O5 inside carbon micropores is particularly attractive to synergize electric-double layer formation and lithium ion intercalation. Here, we demonstrate that hydrated V2O5 can be effectively electrodeposited in carbon micropores of activated carbon cloth. Our study indicates that carbon pores larger than 1 nm are essential for the effective decoration with hydrated V2O5. A thermal treatment after the electrodeposition is often used to enhance the crystal structure of hydrated V2O5. However, thermal annealing of the hydrated vanadium pentoxide decorated activated carbon cloth under an oxygen-rich environment at high temperature (>330 °C) leads to a significant loss of pore volume, leading to a decreased electrochemical performance. At low annealing temperature (200 °C), the vanadium pentoxide electrodeposited activated carbon cloth electrode exhibits a maximum specific capacity of 137 mA h g−1 with stable cycle performance over 1600 cycles at a rate of 4C.

We fabricated cost-effective Cu2−xO/Cu/Cu2−xO multilayer grid electrodes using roll-to-roll (RTR) sputtering and patterning processes for use as transparent and flexible electrodes in flexible smart windows. To optimize the patterned Cu2−xO/Cu/Cu2−xO multilayer grid, the electrical and optical properties of the Cu2−xO/Cu/Cu2−xO multilayer grid electrodes were investigated as a function of grid width and pitch, which directly influence the filling factor of the grid. At the optimized grid width of 16 and pitch of 600 μm, the Cu2−xO/Cu/Cu2−xO multilayer grid had a sheet resistance of 7.17 Ohm per square and an optical transmittance of 87.6%. In addition, the mechanical properties of the optimized Cu2−xO/Cu/Cu2−xO multilayer grid electrode was compared to those of brittle ITO electrodes to demonstrate its outstanding flexibility. To show the potential of the Cu2−xO/Cu/Cu2−xO multilayer grid for smart windows, we fabricated a flexible and transparent thin film heater (TFH) and a flexible electrochromic (EC) device, which are key components of smart windows. The low saturation voltage of the Cu2−xO/Cu/Cu2−xO grid-based TFH and the fast on–off performance of the Cu2−xO/Cu/Cu2−xO grid-based EC device indicates that the RTR-processed Cu2−xO/Cu/Cu2−xO multilayer grid is promising as a low-cost and large-area flexible transparent electrode for high-performance smart windows.

Regioregular polymer semiconductors have demonstrated a well-ordered micro-crystalline morphology in thin films due to better π-stacking orientation resulting in efficient charge transport. We propose an effective synthetic strategy to achieve well-defined regioregular alternative donor–acceptor (D–A) type conjugated polymers using large molecular weight regioregular monomers. Using this synthetic route, various conjugated moieties can be systematically introduced in a single polymer backbone, and we developed a regioregular alternative D–A polymer, coded rr-PBTTh, based on thiophene as electron donating and benzothiadiazole as electron withdrawing groups. This new polymer possesses a highly planar conjugated backbone due to regioregularity and S⋯O and S⋯F non-covalent intramolecular conformational locks. rr-PBTTh exhibits well-balanced ambipolar transport characteristics mainly due to the balanced D–A molecular structure, and shows promising electrochromic performance with coloration efficiency up to 321.7 cm2 C−1 and rapid response time below 0.5 s.

Electrochemical water-splitting is an environmentally friendly and sustainable means of producing oxygen and hydrogen gasses. However, the high cost and poor stability of conventional electrocatalysts, which are based on precious metals, hinder the large-scale commercialization of this technique. Therefore, the current research demands development of highly active catalysts which do not require any precious metal. Herein, we report the fabrication of a Co(OH)2 electrocatalyst on a metallic Cu film supported on a Ni foam substrate. The developed electrocatalyst has dense Co(OH)2 nano-flakes on the Cu film and exhibits excellent performance towards the oxygen evolution reaction in an alkaline solution. A current density of 10 mA/cm2 can be achieved at an overpotential of 325 mV and the catalyst has a small Tafel slope value of only 77 mV/dec. In addition, the catalytic reaction remains stable for 20 h of chronoamperometry test without any noticeable decay. The promising catalytic performance of this catalyst is attributed to the synergistic effect between the Co(OH)2 electrocatalyst and the Cu-modified Ni foam.

We demonstrate novel high-performance electrochromic polymer (LGC-D148) films which contain a diketopyrrolopyrrole (DPP) as the acceptor and thiophene with 2,5-difluorophenylene-dithiophene as the donor. The polymer films undergo highly reversible and long-term stable electrochemical reactions and exhibit distinctive redox peaks. In situ optical measurements reveal that the LGC-D148 films have green/transparent electrochromism with a fast switching speed and a coloration efficiency of >900cm2/C. Keywords: Diketopyrrolopyrrole (DPP), Thiophene, Donor-acceptor random copolymers, Electrochromism, Green coloration

Organic electrochromic (EC) materials are generally known to be electrochemically unstable during the ion intercalation/deintercalation process. One effective method to stabilize them is incorporating graphene derivatives in the polymer matrix, thereby creating strong interaction between graphene derivatives and polymer. However, previous studies are limited to specific polymers and bulk-blended systems, such as mixing the polymer with graphene derivatives. In this study, we developed a polymer-graphene derivative complex with the chemical assistance of a surfactant (octadecylamine, ODA). Graphene oxide (GO) was introduced as a protective layer on the electrochromic poly(3-hexyl thiophene) (P3HT) films by the Langmuir-Schaefer method. The deposition of the GO-ODA protective layer with high coverage was confirmed by atomic force microscopy and high-resolution X-ray reflectivity. The strong interactions between GO-ODA and P3HT were examined with UV-vis spectrophotometry and X-ray photoelectron spectroscopy. Electrochemical and electrochromic investigations revealed that the GO-ODA layer greatly improved the long-term cyclability of the P3HT film. These findings imply that the GO-ODA complex can significantly stabilize the EC cycling, due to its strong interaction with the P3HT film.

Electrochromism refers to the phenomenon where optical changes in a material occur during electrochemical reactions under an applied voltage. Because of advantages such as high contrast and low operating voltage, electrochromic (EC) devices have been widely used in smart windows, switchable mirrors, optical shutters, and information displays.Such devices are usually fabricated on a rigid glass substrate to permit their use in automobile and building applications, which require long-term stability under climatic conditions. However, the use of soft polymer or textile substrates has increased the versatility of such technology, allowing the fabrication of novel flexible, stretchable, and wearable EC devices. Since the first flexible EC devices using WO3layers were developed in 1995 a wide variety of inorganic and organic materials has been investigated with respect to their compatibility with flexible substrates. However, most EC devices fabricated using these materials showed poor performances, especially in terms of coloration speed and long-term stability, which was mainly due to the electrical and mechanical properties of the flexible substrate. In addition, the large area and cost-effective roll-to-roll (RTR) coating process for transparent electrodes has been demonstrated for the fabrication of low cost flexible EC devices. To date, the most common transparent electrode for EC devices is indium-tin-oxide (ITO) due to its low resistivity, high transparency, and mature mass production via processes such as sputtering. Amorphous ITO(a -ITO) films can easily be coated on a flexible substrate using conventional DC sputtering at ambient temperatures, but the high sheet resistance and brittleness of thick a-ITO films prevents their use for flexible and transparent EC devices. Oxide-metal-oxide(OMO) multilayer films have been extensively reported in flexible optoelectronic devices as an alternative to a-ITOfilms. However, there are few reports regarding flexible and transparent EC devices fabricated using OMO multilayer electrodes. The development of a conductive layer with high electrical conductivity and stable mechanical flexibility is greatly needed for flexible EC device applications. In this paper, we report the electrochromic properties of poly(3-hexylthiophene) (P3HT) films coated on ITO/Ag/ITO (IAI) multilayers deposited on flexible PET substrates using an ambient temperature RTR sputtering system. By continuous sputtering of ITO/Ag/ITO layers on the flexible PET substrate, we realized highly transparent, flexible, and conductive electrodes for flexible and transparent EC devices. We characterized the coloration efficiency, response time, and long-term stability of the P3HT on the flexible substrate compared to the material prepared on glass substrates.

The level of CO2 in the atmosphere has increased rapidly due to vast quantities of fossil fuel combustion emissions, and it is accelerating global warming. Hence, pre- and post-combustion CO2 capture and storage (CCS) has become a vital necessity. Cost-effective and efficient nanoporous adsorbents for pre- and post-combustion CO2 capture were developed in this study. The highly porous and oxygen-rich carbon adsorbents were prepared in a facile one-pot process via the direct chemical activation of a molecularly imprinted polymer (MIP) and a MIP composite with activated carbon. The porous carbon adsorbent prepared from the MIP composite had a large specific surface area and specific pore volume of 3010 m2 g−1 and 1.506 cm3 g−1, respectively. Its bimodal pore structure contained micropores and mesopores. This nanoporous carbon adsorbent was rich in electron-dense oxygen presented in a variety of oxygen surface functional groups, which was also advantageous for CCS. These merits afforded selective CO2 adsorption and a high storage capacity under pre- and post-combustion conditions. The efficient carbon adsorbent can be stored 22.1 mmol g−1 and 3 mmol g−1 of CO2 at 25 bar and 1 bar, respectably, which was in the upper range of values reported for porous carbon. Selective CO2 capture by the carbon adsorbents was confirmed by evaluating their selectivity in CO2/CH4, CO2/N2, and CO2/H2 binary gas mixtures at 298 K based on the ideal adsorbed solution theory (IAST). The most effective adsorbent had CO2/H2 (40:60) and CO2/N2 (50:50) selectivity of 534 and 22.6, respectively. The isosteric heat of CO2 adsorption on the porous carbon adsorbents further corroborated the selective CO2 capture.

We demonstrate that hybrid structures of graphene and single-walled carbon nanotubes (SWNTs) are precisely controlled at the liquid–gas interface. The functionalized SWNT Langmuir monolayers anchor single-layer graphene nanosheets (GNSs) suspended in water via Coulomb interaction at the interface. This GNS/SWNT hybrid multilayer electrode can be a promising anode material for Li-ion batteries, offering high specific capacity, outstanding power capability, and excellent cyclability.

We fabricated cost-effective Cu

In this study, we demonstrate the photoelectrochromic devices composed of TiO 2 and WO 3 nanostructuresprepared by anodization method. The morphology and the crystal structure of anodized TiO 2 nanotubes and WO 3 nan-oporous layers are investigated by SEM and XRD. To fabricate a transparent photoelectrode on FTO substrate, a TiO 2 nanotube membrane, which has been detached from Ti substrate, is transferred to FTO substrate and annealed at 450°Cfor 1 hr. The photoelectrode of TiO 2 nanotube and the counter electrode of WO 3 nanoporous layer are assembled andthe inner space is filled with a liquid electrolyte containing 0.5 M LiI and 5 mM I 2 as a redox mediator. The propertiesof the photoelectrochromic devices is investigated and Pt-WO 3 electrode system shows better electrochromic perform-ance compared toWO 3 electrode. Keywords: Electrochromism, Photoelectrochromic Devices, TiO 2 nanotubes, WO 3 nanoporous layers, Anodization ······························································································································· ·································································································

Tungsten trioxide thin films are successfully synthesized by a sol-gel method using tungsten hexachlorideas precursors. The structural, chemical, and optical properties of the prepared films are characterized by scanning elec-tron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-Vis spectrophotometry. The electrochem-ical and electrochromic properties of the films before and after heat treatment are also investigated by cyclicvoltammetry, chronoamperometry, and in situ transmittance measurement system. Compared to as-prepared films, heat-treated tungsten trioxide thin films exhibit a higher electrochemical reversibility of 0.81 and superior coloration effi-ciency of 65.7 cm 2 /C, which implies that heat treatment at an appropriate temperature is a crucial process in a sol-gelmethod for having a better electrochromic performance.Keywords: Electrochromism, Tungsten trioxide, Sol-gel, Heat treatment, Coloration efficiency ······························································································································· ·································································································

The main purpose of this study is to evaluate the awareness survey on the experience of fire fighting safety education and living safety consciousness of college students in the department of noncommissioned officer. Additionally, making provision of basic references and the effective fire fighting safety education is another important purpose of this study. In order to evaluate the awareness, the survey consist of 43 queries based on 6 queries for general characters, 9 queries for experiences of fire fighting safety education and 30 queries for living safety consciousness. The collected data from survey was analyzed using SPSS 20.0 win program. The interrelationship for general characters was confirmed using analysis of frequency, percentage, independent T-tset, ANONVA analysis, and regression analysis. The results show that the experience of fire fighting safety education and living safety consciousness of students from the combatant branch and ordnance corps are higher than those students from quartermaster corps. This may be attributed to the presence or absence of safety relevant courses on a curriculum. Therefore, the presence of safety courses on a curriculum should be one of important points for improving the experience of fire fighting safety education and living safety consciousness of these college students.

We investigated the enhanced electrochemical and electrochromic properties of P3HT (poly 3-hexylthiophene)/WO3 composites. Nanoporous WO3 layers were prepared using electrochemical anodization. P3HT was spin coated on these layers to obtain hybrid P3HT/WO3 composites. After annealing at 300 °C for 1 h, the monoclinic phase of the WO3 layer and self-organized lamella structure of P3HT were examined. The P3HT/WO3 composites exhibited enhanced current densities and three different reflective colors with a combination of pristine P3HT and WO3 during the redox reaction. Furthermore, the composites exhibited faster switching speeds compared with WO3 layers, which might be attributed to the easy Li+ insertion/extraction resulting from the incorporation of P3HT. Keywords: P3HT/WO3 composites, Nanoporous WO3 layers, Electrochromism, Multi-color, Response time

We report on high-performance organic field-effect transistors (OFETs) with low-cost Mo source/drain electrode by incorporating solution-processed V2O5 thin-film interlayers. The original V2O5 powder of orange color is dissolved in NH3 solvent (0.5 wt%) and changed into a transparent solution after moderate heating. We are able to fabricate V2O5 thin films (1–6 nm) on Mo electrodes by simple spin-coating. Kelvin probe measurements reveal that the work function of the Mo electrodes progressively changed from 4.4 to 4.9 eV. With the insertion of the V2O5 layer, OFETs gained significantly improved p-type performance for both regioregular poly(3-hexylthiophene) (rr-P3HT) and ambipolar 3,6-Bis-(5bromo-thiophen-2-yl)-N,N-bis(2-octyl-1-dodecyl)-1,4-dioxo-pyrrolo[3,4-c]pyrrole (DPPT-TT) polymer semiconductors. OFETs on the basis of rr-P3HT or DPPT-TT with V2O5/Mo electrodes exhibit field-effect mobilities of 0.15 and 1.91 cm2/V s, respectively, highly improved from 0.05 and 1.2 cm2/V s in case of OFETs with bare Mo. This performance is already comparable with that of OFETs employing much more expensive Au electrodes. After investigating the contact resistance, we propose that the improvement relies on balancing two factors: modulating the injection barrier by tuning the work function, and manipulating the tunnel distance by controlling the film thickness.

A hybrid membrane pseudocapacitive deionization (MPDI) system consisting of a hydrated vanadium pentoxide (hV2O5)-decorated multi-walled carbon nanotube (MWCNT) electrode and one activated carbon electrode enables sodium ions to be removed by pseudocapacitive intercalation with the MWCNT–hV2O5 electrode and chloride ion to be removed by non-faradaic electrosorption of the porous carbon electrode. The MWCNT–hV2O5 electrode was synthesized by electrochemical deposition of hydrated vanadium pentoxide on the MWCNT paper. The stable electrochemical operating window for the MWCNT–hV2O5 electrode was between −0.5 V and +0.4 V versus Ag/AgCl, which provided a specific capacity of 44 mAh g−1 (corresponding with 244 F g−1) in aqueous 1 m NaCl. The desalination performance of the MPDI system was investigated in aqueous 200 mm NaCl (brackish water) and 600 mm NaCl (seawater) solutions. With the aid of an anion and a cation exchange membrane, the MPDI hybrid cell was operated from −0.4 to +0.8 V cell voltage without crossing the reduction and oxidation potential limit of both electrodes. For the 600 mm NaCl solution, the NaCl salt adsorption capacity of the cell was 23.6±2.2 mg g−1, which is equivalent to 35.7±3.3 mg g−1 normalized to the mass of the MWCNT–hV2O5 electrode. Additionally, we propose a normalization method for the electrode material with faradaic reactions based on sodium uptake capacities.

•We investigated the preparation of Cu2S thin film by chemical bath deposition.•The Cu2S films were characterized using electrochemical techniques.•In addition, the Cu2S films were investigated as a counter electrode in QSSCs.

We examined double-layered transparent conducting oxide (TCO) anode structures consisted of zinc-doped indium oxide (IZO) over the gallium-doped zinc oxide (GZO), and IZO over the GZO with electrochemical treatment. In bottom type OLEDs, power efficiency and current efficiency were enhanced by a factor of 1.50 and 1.14 at a current density of 10 mA/cm2 in IZO/GZO anode structure, compared to the only IZO anode structure. Due to the reduced sheet resistance of the IZO/GZO TCO surface, the operating voltage of the OLED with IZO/GZO anode structure was lowered, leading to mostly enhance power efficiency. More enhanced in power efficiency and current efficiency by a factor of 1.21 and 1.25 at a current density of 10 mA/cm2 were achieved in IZO/GZO anode structure with electrochemical treatment, compared to the IZO/GZO anode structure due to the change of the surface morphology of the GZO and the existence of the nanoporous layer beneath the GZO surface by an electrochemical treatment. In total, double-layered IZO/GZO anode structure with electrochemical treatment was revealed at an enhancement factor of 1.80 in power efficiency and 1.42 in current efficiency, compared to the only IZO anode structure.

The morphology of TiO 2 nanotube layers fabricated by electrochemical anodization in an ethylene glycol solution containing 0.5 wt% NH 4 F was investigated as a function of several voltage conditions. The effects of voltage sweep rate, retention time, and initial sweep voltage on the surface pore structure and tube length were observed in detail by scanning electron microscopy (SEM). It was clearly seen that worm-like porous structures on the TiO 2 nanotube layers were formed during the voltage sweep process. These porous structures changed to round-shaped individual pores with longer tubular layers under constant voltage conditions. The initial sweep voltage also affected the pore size, even when the same final voltage was applied. These findings indicate that voltage conditions are very important factors in determining the surface and layer structure of anodized TiO 2 nanotubes.

Chemical functionalization of carbon nanotubes (CNTs) can strongly affect the efficiency of solar cells due to change of three factors viz. electronic energy structures, interfacial resistance, and electrical field. Therefore, it is worthwhile to investigate the influence of these three factors on the solar cells based on the functionalization of various active molecules in CNTs. In the present study, we investigate the influence of the three factors in the efficiency of superstrate-type Cu(In,Ga)Se 2 (CIGS) solar cells [i.e. F-doped SnO 2 /CNTs/CdS/CIGS/Au] by encapsulation of electron withdrawing and donating organic molecules inside CNTs. The CIGS solar cell was characterized using the electronic diagram, electrochemical impendence spectroscopy, reverse field emission currents, and currents–voltages curves.

Poly(p-phenylene vinylene) (PPV) derivatives with 2,5-diphenyl-1,3,4-oxadiazole-diyl (OXD) as the side chain, poly[2-{4-[5-(4-(heptyloxy)phenyl)-1,3,4-oxadiazole-2-yI]phenyl-oxy}-1,4-phenylene-vinylene] (OXH-PPV), poly[2-{4-[5-(4-(heptyloxy)phenyl)-1,3,4-oxadia-zole-2-yl]phenyl-oxy}-1,4-phenylenevinylene-co-2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (OXH-PPV-co-MEH-PPV), and poly[2-methoxy-5-(2'-ethylhexyl-oxy)-p-phenylene vinylene] (MEH-PPV), were synthesized via a modified Gilch route. The electron-deficient oxadiazole moiety was introduced on the side chain of the polymer backbone to increase the electron-affinity of the polymers. The electroluminescent (EL) properties of the resulting polymers as an active layer, were investigated by the fabrication of single-layer LEDs and the devices using OXH-PPV-co-MEH-PPV showed better EL properties than those using pure MEH-PPV. Also, to investigate the switching properties of the resulting polymers as an active layer, OFET devices were fabricated in a top-contact/bottom-gate configuration. The resulting FETs exhibited typical p-channel characteristics, field-effect mobility of 6.5 x 10(-4) - 7.0 x 10(-5) cm2 V(-1) s(-1), and on-off ratio of about 10(4)-10(5).

Nanobranched TiO 2 nanotubes (TONTs) were synthesized by a sol–gel dipping method for the formation of seed layer, followed by a solution-phase deposition process. The different concentrations of seed solution influence the density of nanobranches on the top surface of TONT, achieving complete surface coverage of nanobranches in 10 mM TiCl 4 seed solution relative to 5 mM TiCl 4 seed solution. With a control sample of bare TONT, the nanobranched TONTs were explored as a photoanode for dye-sensitized solar cells (DSSCs). In the 5 mM TiCl 4 seed solution, the nanotree-shaped branches were sporadically formed on the top surface of TONT, with little effect on the photocurrent-voltage (J–V) properties, while in the 10 mM TiCl 4 seed solution, J sc and fill factor increased, which may have been on account of the increased surface area and light scattering effect from rutile nanobranches, whereas the fill factor may be also increased by the electron transport property, leading to the degraded charge recombination. Accordingly, the nanobranched TONT showed 33% improved efficiency compared to bare TONT.

We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows.

The present work demonstrates that morphology of TiO2–WO3 composite nanotubes formed by alloy anodization can be tuned by controlling applied voltages and time. Distinctive tube morphology can be formed by applying a voltage of more than 80 V. Nanotube diameter and length have a linear relationship with the anodization voltage with a current efficiency of almost 100 %. Furthermore, compared to pure TiO2, the composite nanotubes show a very uniform tube diameter along the tube axis even at the extended anodization time.

Chemical bath deposition is an attractive technique to form single- and multilayered metal oxide/chalcogenide films on electrode surfaces. However, the occurrence of desorption and/or ion-exchange reaction during subsequent chemical bath deposition has so far limited preparation of multilayered metal oxide/chalcogenide films. In this paper, we report a method to prevent desorption and ion-exchange reaction of metal oxide/chalcogenide on electrode surfaces using a polyelectrolyte multilayer during sequential chemical bath deposition. By controlling the ion permeability of the polyelectrolyte multilayer, Cu(2-x)Se film was successfully deposited on the CdS film. The Cu(2-x)Se/CdS film is confirmed by UV-vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray powder diffractometer. Furthermore, the Cu(2-x)Se/CdS films were investigated as photoinduced charge transfer devices which showed photocurrents of 0.22 mA/cm(2) under illumination (I = 100 mW/cm(2)).

An acetylene polymer is formed on single-walled carbon nanotubes (SWNTs) using in situ polymerization. The acetylene polymers/SWNTs composite is hydrophilic even water-soluble, and has a structure of donor/acceptor dyad. In measurements of photocurrents-voltage curves, the composite film exhibits a power conversion efficiency of 1.50 x 10(-2%) under illumination (I = 80 mW/cm2, air mass 1.5 condition).

A thin film of iodine doped polythiophene was grown photoelectrochemically around the dye-sensitized TiO(2) nanoparticles in a Grätzel cell, and the effect of iodine doping level on the cell performance was investigated using X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and photovoltage decay. At an optimum doping level, the cell demonstrated the enhanced energy conversion efficiency by 27.52% compared to the cell without polythiophene.

We investigated the effects of a gate dielectric and its solvent on the characteristics of top-gated organic fieldeffect transistors (OFETs). Despite the rough top surface of the inkjet-printed active features, the charge transport in an OFET is still favorable, with no significant degradation in performance. Moreover, the characteristics of the OFETs showed a strong dependency on the gate dielectrics used and its orthogonal solvents. Poly(3hexylthiophene) OFETs with a poly(methyl methacrylate) dielectric showed typical p-type OFET characteristics. The selection of gate dielectric and solvent is very important to achieve high-performance organic electronic circuits.

To increase the efficiency of TiO 2 nanotube-based dye-sensitized solar cells, we fabricated TiO 2 nanotubes and decorated them with ZnO rod-like nanostructures via anodization of Ti metal sheets followed by the hydrothermal growth of ZnO. Compared to conventionally anodized nanotubes, the modified nanotubes provided a higher specific surface area for dye adsorption. Besides increased dye adsorption, suppression of the recombination of photo-induced electrons at the electrode/electrolyte interface was observed in the modified nanotube-based systems because of the existence of a ZnO thin layer on the surface of nanotubes. This thin layer was applied as a seed for an oriented growth of ZnO. Dye-sensitized solar cells based on TiO 2 nanotubes decorated with ZnO rod-like nanostructures showed a higher power conversion efficiency of 3.84%, compared to standard nanotube devices with an efficiency of 2.06%.

TiO(2) is one of the most investigated compounds in contemporary materials science. Due to a set of virtually unique electronic properties, it finds intense use in photoelectrochemical applications such as photocatalysis or solar cells. The main drawback in view of direct exploitation of solar-light-based effects is its large band gap of >3 eV. Visible-light-activated TiO(2) can be prepared by doping (band-gap engineering) through incorporation or decoration with other metal ions, nonmetal ions, and semiconductors. Most recently, efforts in TiO(2) research have been even more intensified by the finding of self-organized nanotubular oxide architectures that can be prepared by a simple but optimized anodization of Ti metal surfaces. These nanotubular geometries provide large potential for enhanced and novel functional features. This Review examines doped TiO(2) and in particular TiO(2) nanotubes. Various types of dopants, doping methods, and applications of modified TiO(2) nanotubes are discussed.

Initiated by the work of Fujishima and Honda in 1972, over the past decades, the use of particulate or colloidal semiconductors in solutions has extensively been studied for the photocatalytic oxidation of organic waste and pollutants in water. By far the most studied material is TiO2, as it is considered to represent the most suitable photocatalyst, in view of effectiveness and stability against photodecomposition. Typically these photocatalytic systems are used in form of nanoparticles, either freely suspended in solution or compacted to a robust photoelectrode. Earlier studies mainly focused on geometric parameters of the particles that influence the photocatalytic activity, such as surface area, size distribution in solution, as well as the TiO2 crystal structure, which was found to play a crucial role. Later, various approaches were reported to enhance the photocatalytic activity of TiO2, for example, by decorating the surface of TiO2 nanoparticles with noble metals such as Pt, Pd, Ag, Au, and so forth. More recently, improved photocatalytic activity was reached by modifying TiO2 particles with other oxides (such as CrxOy, FexOy, VxOy, MoOx, WOx, etc.). The effect of noble particle decoration was mainly interpreted in terms of a facilitated contribution of the photoexcited electrons in the photocatalytic reaction producing, for example, superoxide from O2 dissolved in aqueous electrolytes, while decoration with other oxides particles may influence the rate of charge transfer to the environment via surface states or junction formation. In general, two main reactions are considered to be relevant for the photocatalytic activity of TiO2: 1) the generation of valence-band holes that upon ejection to the environment (electrolyte) have an oxidative power sufficient to oxidize almost any organic material and 2) conduction-band electrons ejected to the electrolyte that may form reactive superoxides. Most recently, advanced geometries of TiO2 have been increasingly explored, in particular self-ordered TiO2 nanotubes (TiNT) have attracted wide attention due to the high level of geometrical definition combined with a high surface area (for an overview see references [23–26]). Such self-ordered TiO2 nanotubular layers can easily be grown on Ti metal sheets by a simple but optimized electrochemical anodization in F containing electrolytes. 28] Investigations of their photocatalytic properties have shown that these tubular layers can be more efficient than classical nanoparticulate layers of a comparable thickness. Self-ordered oxide nanotubes cannot only be grown on pure Ti, but also on other transition metals such as Mo, W, Ta, Nb, and so forth, and a full range of Ti alloys including TiW, TiNb, TiAl, TiMo, TiTa. In the present work, we demonstrate a very strong effect of tungsten addition to the TiO2 nanotubes in terms of their photocatalytic activity. For this, different TiW alloys (Ti0.2at%W (Ti0.2W) and Ti9at%W (Ti9W)) as well as pure Ti were anodized to form 2 mm-long self-organized tube layers as shown in Figure 1. To achieve these self-organized layers different anodization conditions had to be applied as outlined in the Supporting Information. For all cases, comparable dimensions of nanotubular layers with a tube length between 2.2 mm to 2.6 mm and a diameter (obtained from SEM cross sections) between 85 nm to 100 nm were used. For the TiW alloys (Figure 1a–d), a thin porous initiation layer is present on the top of the highly ordered nanotubes, as visible in the cross-sectional images of Figure 1b and d. Figure 1e and f show for comparison, the top view and cross section of pure TiO2 nanotube layers. The top layer can be removed, but this was found to not affect the results strongly. [a] I. Paramasivam, Y.-C. Nah, C. Das, N. K. Shrestha, Prof. Dr. P. Schmuki Department of Materials Science WW-4 Institute of Corrosion and Surface Science (LKO) University of Erlangen—N rnberg Martensstr.7, 91058 Erlangen (Germany) Fax: (+49)9131-852-7575 E-mail : schmuki@ww.uni-erlangen.de Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.201000397. It contains experimental descriptions, XRD patterns of TiO2-WO3 nanotubes at 350 8C and 550 8C, and EDX of elemental compositions for Ti9W and Ti0.2W.