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Semiconducting two-dimensional materials have gained significant attention in the field of electronics due to their exotic physical properties. In this study, multilayer WS2 films were achieved by employing a layer-by-layer wet transfer method from monolayer WS2 films synthesized through chemical vapor deposition. Analysis of photoluminescence and Raman spectra indicated a weak interaction between layers in the multilayer WS2 films. The electron mobility of WS2—based field effect transistors was significantly affected by the number of layers, with trilayer films exhibiting the highest mobility. Moreover, the FETs exhibited operational ability in ambient conditions, showing enhanced performance when utilizing HfO2 as the capping layer. Our findings provide a feasible way to achieve multilayer WS2 for high-performance FETs. [ABSTRACT FROM AUTHOR]

Van der Waals (vdW) heterostructures have gained significant attention in photodetectors due to their seamless integration with materials possessing diverse functionalities. In this study, the fabrication of a Te nanomesh/black‐Si vdW heterostructure is presented, and investigated its photoresponse properties. The heterostructure exhibits a pronounced rectification behavior, characterized by a rectification ratio of 2.2 × 104. Notably, the heterostructure device demonstrates commendable photoresponse properties, including a high responsivity of 350 mA W−1, an extensive linear dynamic range of 45.5 dB, a high specific detectivity of 9.6 × 1011 Jones, and a wide spectral response ranging from 400 to 1550 nm. Furthermore, the heterostructure exhibits rapid response, with a rise time and a decay time of 70 and 140 µs, respectively. These exceptional photoresponse properties can be attributed to the robust internal built‐in electrical field at the hetero‐interface and the augmented light absorption in black‐Si. The outstanding photoresponse properties of the heterostructure make it a promising candidate for multiwavelength single‐pixel imaging, enabling the collection of mask patterns under varying wavelengths of light radiation. This work provides a novel approach for fabricating mixed‐dimensional vdW heterostructures, offering promising prospects for advancements in optoelectronics. [ABSTRACT FROM AUTHOR]

Due to excellent electrical and optoelectronic properties, 2D transition metal dichalcogenides and their van der Waals (vdW) heterostructures have attracted great attention for broadband optoelectronics. Here, an unreported vdW PdSe2/WS2 heterostructure is developed for robust high‐performance broadband photodetection from visible to infrared optical communication band. These heterostructure devices are simply formed by direct selenization of Pd films pre‐deposited on the chemical vapor deposited monolayer WS2, followed by wet‐transfer onto device substrates with pre‐patterned electrodes. Importantly, the obtained heterostructure device exhibits an impressive broadband spectral photoresponse with response times less than 100 ms for different wavelength regions (532 to 1550 nm), where this performance is significantly better than that of pristine monolayer WS2 devices. This performance enhancement is attributed to the type I band alignment of the heterostructure. Under illumination, both intralayer and interlayer excitations are involved to generate carriers in the relevant layer, enabling the broadband photoresponse. Photocarriers would then undergo charge separation in the depletion region with electrons transferred into the charge transport layer of WS2 through the built‐in electric field, followed by the relaxation to valance band via interlayer or intralayer transition. All these findings can indicate the promising potential of vdW PdSe2/WS2 heterostructures for next‐generation high‐performance optoelectronics. [ABSTRACT FROM AUTHOR]

Interlayer charge‐transfer (CT) in 2D atomically thin vertical stacks heterostructures offers an unparalleled new approach to regulation of device performance in optoelectronic and photonics applications. Despite the fact that the saturable absorption (SA) in 2D heterostructures involves highly efficient optical modulation in the space and time domain, the lack of explicit SA regulation mechanism at the nanoscale prevents this feature from realizing nanophotonic modulation. Here, the enhancement of SA response via CT in WS2/graphene vertical heterostructure is proposed and the related mechanism is demonstrated through simulations and experiments. Leveraging this mechanism, CT‐induced SA enhancement can be expanded to a wide range of nonlinear optical modulation applications for 2D materials. The results suggest that CT between 2D heterostructures enables efficient nonlinear optical response regulation. [ABSTRACT FROM AUTHOR]

With distinct ion insertion-induced tinting behavior, tungsten oxide (WO 3 ) has been intensively studied as a representative electrochromic (EC) material for many years. To enhance its EC properties, strategies including nanostructuring, plasmonic engineering, and metal ion doping have been adopted. Here, we show that rare earth element of gadolinium (Gd) doping can effectively improve the coloration efficiency ( η ) of a sputtered amorphous WO 3 (∼30% enhancement at the maximum of eye-sensitive wavelength of 520 nm for 0.57 wt% doping). By combining the film structural characterization and electrochemical analysis, such an increment can be attributed to the monoclinic Gd 2 O 3 nanoislands formed on WO 3 surface which enhanced charge capacity and reaction kinetics of the film. The large transmittance modulation (76% at 800 nm), high coloration efficiency (68.3 cm 2  C −1 at 633 nm) and fast switching speed (7.8 and 10.4 s for coloration and bleach time, respectively) were achieved for the modest Gd-doped WO 3 film (0.9%). However, further increasing of Gd doping results in decreasing of η , which could be attributed to the excess amount of Gd 2 O 3 that inhibits the penetration of electrolyte into the active material. We believe that the understanding of the Gd-doping effect on the electrochemical behaviours of WO 3 may shed light on selecting the proper doping elements and their concentration for energy-saving smart windows. [ABSTRACT FROM AUTHOR]

Multiwall carbon nanotubes (CNTs) were synthesized by the annealing of carbonaceous solid at a low-temperature (450 °C). The average diameter of the CNTs is about 50 nm. The length of the CNTs ranges from 200 nm to nearly 1 μm. The as-synthesized CNTs are crystallized. Cobalt nanoparticle is capped at the tip of the CNT. The carbonaceous solid, which contains cobalt nanoparticles, was obtained by the sol–gel autocombustion method. The growth of CNTs occurred in the annealing process, while the combustion process only produced carbonaceous solid and cobalt nanoparticles. The cobalt nanoparticles catalyze the decomposition of carbonaceous solid into carbonaceous gas species, and also catalyze the growth of CNTs during the annealing process. [ABSTRACT FROM AUTHOR]

As a candidate for transparent electrodes, oxide–metal–oxide tri-layer films have attracted a lot of interest by virtue of their low cost and decent performance. However, their thermal stability needs to be considered before device integration. Here, we report a thermal annealing effect on the performance of WO 3 –Ag–WO 3 (WAW) transparent conductive thin film prepared by thermal evaporation. We find that the sheet resistance of the as-prepared WAW film gradually increases from 6.55 to 21.4 Ω/sq when the annealing temperature reaches 400 °C. With a low annealing temperature (below 200 °C), the luminous transmittance of the WAW film slightly increases but decreases rapidly when the annealing temperature exceeds 200 °C. The maximum figure of merit (11 × 10 − 3 Ω − 1 ) was obtained at the annealing temperature of 100 °C. Above the annealing temperature of 300 °C, the film shows significant transmittance and conductivity degradation, which can be attributed to the decrease of intrinsic dielectric constant of WO 3 layers and the reduction of connectivity between Ag islands upon high temperature annealing, respectively. Annealing at a temperature of 500 °C leads to severe destruction of the tri-layer structure. In addition, we believe that the localized surface plasmonic absorption of annealing-generated Ag nanoparticles results in a valley centered at 410 nm on the transmittance spectrum of the 500 °C annealed WAW film. [ABSTRACT FROM AUTHOR]

Highlights: [•] String-like ZnO/SnO nanowire/nanosheet nano-heterostructures were synthesized. [•] The microstructures of the nano-heterostructures were studied in detail. [•] Blue shift of the band related emission of ZnO from the nanostructures was observed. [Copyright &y& Elsevier]

Abstract: Comb-like CdS nanobelt/ZnO nanorod heterostructures were synthesized by a two-stage method. X-ray diffractometer, scanning electron microscopy, transmission electron microscopy were used to characterize and analyze the as-synthesized products. The results demonstrate that the CdS nanobelt backbones grow along [210] and the ZnO nanorod branches epitaxially grow on the (001) surface of the CdS nanobelt with a growth direction of [001]. The as-prepared heterostructures exhibit an important feature of single-crystallinity. At room temperature, the comb-like CdS nanobelt/ZnO nanorod heterostructures show strong green emission. [Copyright &y& Elsevier]

Abstract: Branched Sn/carbon nanotube (CNT) core/shell structures were synthesized by employing the catalytic chemical vapor deposition method over SnO2 nanowires for the first time. Detailed analysis showed that the backbones are mainly composed of CNTs, and the branches have a core/shell structure with a Sn nanowire as the core and a CNT as the shell. The thickness of the carbon layer capped on the Sn nanowires is about 20nm. The Sn nanowires have lengths of about several micrometers and diameters of about 40nm. A formation mechanism of the branched nanostructures is suggested. [Copyright &y& Elsevier]

Abstract: SnO2/ZnO hierarchical nanostructures were synthesized by a two-step carbon assisted thermal evaporation method. SnO2 nanowires were synthesized in the first step and were then used as substrates for the following growth of ZnO nanowires in the second step. Sn metal droplets were formed at the surfaces of the SnO2 nanowires during the second step and were acted as catalyst to facilitate the growth of ZnO nanowires via vapor–liquid–solid mechanism. Room temperature photoluminescence measurements showed that the SnO2/ZnO hierarchical nanostructures exhibited a strong green emission centered at about 520nm and a weak emission centered at about 380nm. The emissions from the SnO2 were drastically constrained due to screen effect caused by the ZnO layer. [Copyright &y& Elsevier]

Abstract: The synthesis of single crystalline K6Ta10.8O30 nanowires by molten salt method was reported for the first time. X-ray diffraction results indicated that the as-prepared products were pure phase K6Ta10.8O30. Scanning electron microscopy and transmission electron microscopy results showed that the products consisted of wire-like nanostructures with 100–300nm in diameter and several micrometers in length. High resolution electron microscopy and selected area electron diffraction results indicated that the K6Ta10.8O30 nanowires were single crystalline with a growth direction of [001]. The ultraviolet–visible diffuse reflectance measurement showed that the band gap of the nanowires was about 4.1eV. The effects of reaction temperature, time, and weight ratio of the precursor (mixture of K2CO3 and Ta2O5) to KCl salt on the morphology of the products were investigated. [Copyright &y& Elsevier]

Abstract: In this study, we have investigated effective refractive index (ERI) and power confinement factor (PCF) in single nanobelt and coupling between two parallel nanobelts using finite-difference time-domain (FDTD) method. As the width of nanobelt increases, both the effective refractive index (ERI) and power confinement factor (PCF) are increased till the saturation values. The ERI changes linearly with refractive index in our simulation range, while the PCF shows nonlinear characteristic. The coupling length () between two nanobelts is much shorter than that in weakly coupled waveguide, which may find applications in solving the cross talk problem. Nanobelt behaves like slab waveguide when the width becomes big enough. [Copyright &y& Elsevier]

Abstract: Alloyed wurtzite Zn49Cd51S nanocrystals with nearly 15at% Mn doped have been synthesized by the sol–gel auto-combustion method. At this work, the doping level of Mn in nanoscale sulfide semiconductors is substantially higher than early reports, so far as we know. The max doping level was established indirectly by X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy: no impurities were found in the XRD pattern of the product until the doping level was increased to 15at%; a characteristic Mn 585nm emission appeared and the defect related emission diminished in the PL spectrum, when Mn was incorporated into the Zn49Cd51S nanocrystals; and the intensity of Mn 585nm emission decreased rapidly, when the doping level was increased from 5at% to 15at%. Factors that may benefit the Mn doping were discussed. [Copyright &y& Elsevier]

To date, wafer‐scale synthesis of two‐dimensional (2D) materials are well achieved by chemical vapor deposition, but the obtained monolayers typically have multidomains with electrical and optoelectronic properties affected by grain boundaries and domain sizes. When these 2D materials are used as the growth templates, these boundaries would also provide unknown influences to the successive heterostructure formation for extended applications. Here, for the first time, direct visualization of grain boundaries in monolayer WS2 film can be realized by the growth of CdS nanoparticles. Specifically, CdS is found to first preferentially nucleate and form as nanoparticle chains along WS2 grain boundaries in a random manner, independent of the grain boundary characteristics. Due to electron scattering and type II band alignment at the WS2–CdS heterojunction, WS2 reduces in its mobility while becoming enhanced in its electron concentration. Notably, the WS2–CdS heterostructure also yields improved carrier separation and collection for the photodetection performance enhancement. All these results can facilitate the detailed evaluation of crystalline grains‐related information of 2D materials and provide thorough understanding on the effect of these overgrown CdS on underlying WS2 monolayers, being extremely important to further optimize and enable their functionalities for advanced device applications. Grain boundaries in chemical vapor deposited monolayer WS2 induce the growth of CdS nanoparticle chains there, making the grain boundaries visible. This overgrowth of CdS nanoparticles at the WS2 grain boundaries then leads to the formation of a type II heterojunction, which can reduce the carrier mobility while enhancing the photodetection performance of WS2. [ABSTRACT FROM AUTHOR]

Zinc (Zn) has arisen as a significant suppressor of vacancy formation in halide perovskites, establishing its pivotal role in defect engineering for these materials. Herein, the Zn‐catalyzed vapor‐liquid‐solid (VLS) route is reported to render black‐phase CsPbI3 nanowires (NWs) operationally stable at room temperature. Based on first‐principle calculations, the doped Zn2+ can not only lead to the partial crystal lattice distortion but also reduce the formation energy (absolute value) from the black phase to the yellow phase, improving the stability of the desired black‐phase CsPbI3 NWs. A series of contrast tests further confirm the stabilization effect of the Zn‐doped strategy. Besides, the polarization‐sensitive characteristics of black‐phase CsPbI3 NWs are revealed. This work highlights the importance of phase stabilization engineering for CsPbI3 NWs and their potential applications in anisotropic optoelectronics. [ABSTRACT FROM AUTHOR]

Photodetectors with high responsivity, fast response, and broad spectral response are of great importance for a wide range of applications in fundamental science and various industries. However, conventional photodiodes operating at low bias voltage do not provide any gain. The graphene (Gr)/Si van der Waals heterostructure, on the other hand, offers a potential gain due to the limited density of states near the Dirac point. In this work, a highly photoresponsive broadband pyramidal black‐Si/Gr heterojunction photodetector is presented. The device, with an active area of 5×5 mm2 and a bias voltage of −5 V, exhibits an ultra‐high responsivity of 4.1 A W−1. The photoresponsivity can be further increased to 1379 A W−1 by reducing the device area. Comparative experiments reveal that the pyramidal black‐Si/Gr photodetectors exhibit the largest responsivity compared with pyramidal‐Si/Gr and flat‐Si/Gr photodetectors. The gain in pyramidal black‐Si/Gr photodetectors is attributed to both the pyramidal nanoporous structures and the shift of the Fermi level of Gr under bias. Furthermore, the high responsivity and stable operation of the photodetectors enable the demonstration of imaging applications. The results provide a new strategy for enhancing the performance of photodetectors based on 2D materials. [ABSTRACT FROM AUTHOR]

PdSe2, a semiconductor with a narrow band gap, shows tremendous promise for high‐performance broadband photodetectors. In this study, highly sensitive, broadband, and flexible PdSe2 thin film photodetectors on polyimide (PI) substrates that can detect light from the UV (365 nm) to infrared (2200 nm) regions are reported. The devices with thick (21 nm) PdSe2 films show decent performance with a decent responsivity of 37.6 mA W−1 at 1550 nm and a fast response time. For the thick PdSe2 film, the bolometric effect dominates the positive photoresponse across all wavelength regions, whereas for the thin PdSe2 film (4.5–13 nm), which shows both positive and negative photoresponses, it dominates in the infrared region. The negative photoresponse of thin PdSe2 in the UV to the VIS region is attributed to the charge transfer‐related adsorption‐desorption of gas molecules. Detailed investigations revealed that the temperature coefficient of resistance (TCR) value is closely correlated to film thickness, with the thinnest film exhibiting the highest absolute TCR value of up to 4.3% °C−1. The value is much larger than that of metals, most 2D materials, amorphous Si, and even commercial VOx. These findings suggest that PdSe2 films have a promising future in broadband photodetectors. [ABSTRACT FROM AUTHOR]

Atomically thin narrow-bandgap layered PdSe2 has attracted much attention due to its rich and unique electrical properties. For silicon-compatible device integration, direct wafer-scale preparation of high-quality PdSe2 thin film on a silicon substrate is highly desired. Here, we present the low-temperature synthesis of large-area polycrystalline PdSe2 films grown on SiO2/Si substrates by plasma-assisted metal selenization and investigate their charge carrier transport behaviors. Raman analysis, depth-dependent x-ray photoelectron spectroscopy, and cross-sectional transmission electron microscopy were used to reveal the selenization process. The results indicate a structural evolution from initial Pd to intermediate PdSe2– x phase and eventually to PdSe2. The field-effect transistors fabricated from these ultrathin PdSe2 films exhibit strong thickness-dependent transport behaviors. For thinner films (4.5 nm), a record high on/off ratio of 104 was obtained. While for thick ones (11 nm), the maximum hole mobility is about 0.93 cm2 V−1 S−1, which is the record high value ever reported for polycrystalline films. These findings suggest that our low-temperature-metal-selenized PdSe2 films have high quality and show great potential for applications in electrical devices. [ABSTRACT FROM AUTHOR]

The surface of low‐dimensional perovskites play a crucial role in determining their intrinsic property. Understanding their characteristics and the influence of certain surfaces is valuable in designing functional surface‐engineered structures. Meanwhile, surface passivation can also be applied to stabilize and optimize the state‐of‐the‐art perovskite‐based optoelectronics. Herein, cesium lead bromide (CsPbBr3) microwire parallel arrays are designed and fabricated with specific (100)‐terminated crystal planes, which exhibit excellent photodetection performance with long‐term environment stability >3000 h. Notably, it is uncovered experimentally and theoretically that environmental oxygen can not only passivate the Br‐vacancy‐related trap states on the (100) surface, but also create charge carrier nanochannels to enhance the (opto)electronic properties. The coupling effects between oxygen species and the specific terminated crystal planes of perovskites highlight the importance of surface engineering for designing and optimizing perovskite‐based devices. [ABSTRACT FROM AUTHOR]

Bi‐directional photodetection with positive and negative photoconductance (PPC/NPC) plays a critical role in building next‐generation artificial neuromorphic systems, visual information processing and optoelectronic logic gates of the future. However, the typical device configuration based on heterostructures with strict working principles restricts the diversity of material selection. In this work, a novel strategy is proposed to fabricate bi‐directional photoresponse devices based on PtSe2−x films with precisely controllable selenization engineering. It is found that the PtSe2−x films are composed of Pt and PtSe2 components. The direction of the photocurrent can be reversibly modulated in a broadband range by tuning the ratio of PtSe2 in the film, which is ascribed to the synergistic mechanism of bolometric effect of Pt and photoconductive effect of PtSe2. The polarity switching wavelength from NPC to PPC can be further modulated through tuning the components of the film for specific demand. The tunable bi‐directional photoresponse enables the device to mimic the fundamental functions of artificial synapses all optically, such as aversion learning capability and logical functions, with high paired pulse facilitation index. This work potentially opens an opportunity for the development of advanced artificial neuromorphic systems and optoelectronic logic gates. [ABSTRACT FROM AUTHOR]

By combining Gd dopant induction and magnetron sputtering technique, vertically-aligned Gd-doped WO 3 nano-stalagmite arrays (GW-NSs) have been first constructed on the ITO-coated glass substrate, which exhibits a significantly improved electrochromic and capacitive performance. Moreover, an electrochromic energy storage smart window (EESW) device is further fabricated by assembling the GW-NSs electrode and an opposite NiO electrode toward practical bifunctional application. [Display omitted] • Gd-doped WO 3 nano-stalagmites (GW-NSs) array with vertical alignment have been successfully synthesized on ITO-coated glass substrates via co-sputtering method, which can possess optimized aspect ratio and array density by precise parameter optimal design (Gd/W, sputtering times, etc). • The optimized GW-NSs film exhibits a significantly improved electrochromic and capacitive performance, which could be attributed to its large surface area of nano-array structures induced by Gd doping, significantly increasing the number of the active sites and meanwhile facilitate the Li+ ions diffusion. • Dual-functional smart window device assembled with the GW-NSs and NiO counter electrode is demonstrated with ability to visually monitor the level of stored energy from the rapid and reversible color variation, indicating the potential applications of GW-NSs in both electrochromic and energy-storage fields. Gd-doped WO 3 nano-stalagmites (GW-NSs) film has been successfully prepared on indium-doped tin oxide (ITO)-coated glass substrates by co-sputtering deposition. Gd dopants can facilitate the vertically-aligned growth of WO 3 nano-stalagmites on the WO 3 -nanoparticle seed layer. The microstructure analysis shows that the GW-NSs film with optimized aspect ratio and array density is fabricated with Gd/W = 0.6 % in atomic ratio. Such GW-NSs electrode (active area: 1 × 1.5 cm2) exhibits large transmittance modulation (ΔT = 52.7 % at 633 nm), high coloration efficiency (87.3 cm2 C−1 at 633 nm), fast switching speed (5.9/13.1 s for coloration/bleaching), large diffusion coefficient (9.52 × 10−10 cm2 s−1) and long-term cycling stability (>2000) under an applied voltage of ± 1.0 V, which can be attributed to a shorten Li+ diffusion distance and a large-area contact with the electrolyte. Importantly, the GW-NSs film also shows superior capacitive performance (calculated areal capacitance of 8.44 mF cm−2 at 0.4 mA cm−2) and long-term cyclic stability (capacitance retention rate is 87.4 % after 2000 cycles). Furthermore, we fabricated the bifunctional smart window device combined with NiO counterpart electrode, which has the ability to visually monitor the level of stored energy from rapid and reversible coloration, indicating the potential applications of GW-NSs in both electrochromic and energy-storage fields. [ABSTRACT FROM AUTHOR]

High‐performance flexible room‐temperature near‐infrared (NIR) photodetectors are one of the important components for image sensing, data communication, environmental monitoring, and bioimaging applications. However, there is still a lack of suitable device channel materials to provide high sensitivity as well as good mechanical flexibility for photodetection, particularly operating at the optical communication wavelength of 1550 nm. In this work, highly crystalline In0.28Ga0.72Sb nanowires (NWs) are successfully grown by the two‐step chemical vapor deposition method and assembled into high‐density regular NW parallel arrays on polyimide substrates. When they are constructed into photodetectors without using any p–n junctions, they exhibit the excellent responsivity up to 1520 A W−1 and ultra‐fast response speed below 20 µs toward 1550 nm irradiation at room temperature, which constitutes a record high performance among all flexible NIR photodetectors reported in recent literature. Notably, these flexible NW parallel‐array photodetectors also display a superior mechanical flexibility and operation durability. They not only provide a stable photoresponse under illumination on–off cycles up to 1000 s, but also maintain the steady photocurrent without any significant degradation after 700 bending cycles. All these results evidently indicate the promising potential of these crystalline In0.28Ga0.72Sb NW parallel arrays for next‐generation flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]

Due to the energy crisis, the development of high-performance photoelectrocatalysts is becoming a hot research area in recent years. Among the materials studied, BiFeO3 (BFO) exhibits excellent photoelectrocatalytic performance due to its moderate bandgap and unique band structure. In this paper, both pure BFO and La-doped BFO were synthesized by solgel method. The average size of the BFO nanoparticles was tuned from 65 to 440 nm. For the La-doped BFO, the average size of the nanoparticles was reduced from 95 to 40 nm with the increase in doping level from 0 to 30%. Next, the photoelectrocatalytic performance of the pure BFO nanoparticles were enhanced with the reduction in nanoparticle size, which was possibly caused by increased surface-to-volume ratio. For the increase in doping of La, the corresponding photoelectrocatalytic performance was first enhanced and then degraded. To understand the obtained results, a mechanism was proposed, which can be attributed to the competition between geometric size effects and surface effects. Our findings provided a controlled way to tune the photoelectrocatalytic performance of BFO system, which is crucial for practical applications. [ABSTRACT FROM AUTHOR]

Bi-directional, photoresponse, selenization engineering, artificial synapses Keywords: artificial synapses; bi-directional; photoresponse; selenization engineering EN artificial synapses bi-directional photoresponse selenization engineering 1 1 1 08/29/22 20220825 NES 220825 B Tunable Bidirectional Photoresponses b In article number 2205709, Yulong Liao, He Yu, Jun Wang, and co-workers report the first observation of a tunable bidirectional photoresponse in hybrid PtSe SB 2- I x i sb films based on precisely controllable selenization engineering. Tunable Bi-directional Photoresponse in Hybrid PtSe2-x Thin Films Based on Precisely Controllable Selenization Engineering (Adv. Funct. [Extracted from the article]

Nanostructured WO 3 films prepared by an industry compatible method with large surface area and strong adhesive force to the substrate are highly desired for electrochromic (EC) applications. Here, we report the preparation of a kind of WO 3 nanoisland films on indium-doped tin oxide (ITO)-coated glass substrates by Ag-induced reactive sputtering deposition combined with a post-etching treatment. Our study demonstrates that compared with the bare WO 3 film, the nanoisland film exhibits apparently enhanced EC performance, including high luminous transmittance (92.8%) in a bleached state, high luminous coloration efficiency (126.4 cm2/C), relatively fast color-switching time (7.1 s for coloring and 12.1 s for bleaching), decent long-term cycling stability (2000 cycles) and improved self-bleaching ability. Electrochemical kinetics analysis indicates that such enhanced EC performance relies on large lithium-ion diffusion coefficient (2.37 × 10−10 cm2/s), a good ability of charge storage (10.82 mF/cm2), and low charge-transfer resistance (196 Ω) of the nanoisland microstructure. The results shed light on exploring a novel method to prepare high EC performance WO 3 film. Image 1 • WO 3 nanoisland films can be fabricated by Ag-induced magnetron sputter deposition combined with a post-etching treatment, which significantly increases the contact interface between the electrolyte and materials. • The special nanostructure promotes the electrochromic performance eminently: higher optical transmittance (92.8%), coloration efficiency (126.4 cm2/C) and fast response time (7.1 s for coloring and 12.1 s for bleaching). • The electrochemical performance was analyzed to explain the internal cause relying on large ion diffusion coefficient (2.37 × 10−10 cm2/s), good charge storage (10.82 mF/cm2), and low charge-transfer resistance (196 Ω). [ABSTRACT FROM AUTHOR]