Catechol-Coordinated Framework Film-based Micro-Supercapacitors with AC Line Filtering Performance

Coordination polymer frameworks (CPFs) have broad applications due to their excellent features, including stable structure, intrinsic porosity, and others. However, preparation of thin-film CPFs for energy storage and conversion remains a challenge because of poor compatibility between conductive substrates and CPFs and crucial conditions for thin-film preparation. In this work, a CPF film was prepared by the coordination of the anisotropic four-armed ligand and Cu^II at the liquid–liquid interface. Such film-based micro-supercapacitors (MSCs) are fabricated through high-energy scribing and electrolytes soaking. As-fabricated MSCs displayed high volumetric specific capacitance of 121.45 F cm⁻³. Besides, the volumetric energy density of MSCs reached 52.6 mWh cm⁻³, which exceeds the electrochemical performance of most reported CPF-based MSCs. Especially, the device exhibited alternating current (AC) line filtering performance (−84.2° at 120 Hz) and a short resistance capacitance (RC) constant of 0.08 ms. This work not only provides a new CPF for MSCs with AC line filtering performance but also paves the way for thin-film CPFs preparation with versatile applications.     

An Olefin‐Linked Covalent Organic Framework as a Flexible Thin‐Film Electrode for a High‐Performance Micro‐Supercapacitor

Developing effective synthetic strategies as well as enriching functionalities for sp²‐carbon‐linked covalent organic frameworks (COFs) still remains a challenge. Now, taking advantage of a variant of Knoevenagel condensation, a new fully conjugated COF ( g‐C₃₄N₆‐COF ) linked by unsubstituted C=C bonds was synthesized. Integrating 3,5‐dicyano‐2,4,6‐trimethylpyridine and 1,3,5‐triazine units into the molecular framework leads to the enhanced π‐electron communication and electrochemical activity. This COF shows uniform nanofibrous morphology. By assembling it with carbon nanotubes, a flexible thin‐film electrode for a micro‐supercapacitor (MSC) can be easily obtained. The resultant COF‐based MSC shows an areal capacitance of up to 15.2 mF cm^?2, a high energy density of up to 7.3 mWh cm^?3, and remarkable rate capability. These values are among the highest for state‐of‐the‐art MSCs. Moreover, this device exhibits excellent flexibility and integration capability.     

Influence of hole mobility on the response characteristics of p-type nickel oxide thin film based glucose biosensor

RF sputtered p-type nickel oxide (NiO) thin film exhibiting tunable semiconductor character which in turns enhanced its functional properties. NiO thin film with high hole mobility is developed as a potential matrix for the realization of glucose biosensor. NiO thin film prepared under the optimized deposition conditions offer good electrical conductivity (1.5 × 10⁻³ Ω⁻¹-cm⁻¹) with high hole mobility (2.8 cm² V⁻¹ s⁻¹). The bioelectrode (GO_x/NiO/ITO/glass) exhibits a low value of Michaelis–Menten constant (K_m = 1.05 mM), indicating high affinity of the immobilized GO_x toward the analyte (glucose). Due to the high surface coverage (2.32 × 10⁻⁷ mol cm⁻²) of the immobilized enzyme on to the NiO matrix and its high electrocatalytic activity, the prepared biosensor exhibits a high sensitivity of 0.1 mA (mM⁻¹-cm⁻²) and a good linearity from 25 to 300 mg dL⁻¹ of glucose concentration with fast response time of 5 s. Various functional properties of the material (mobility, crystallinity and stress) are found to influence the charge communication feature of NiO thin film matrix to a great extent, resulting in enhanced sensing response characteristics.     

Electrical conductivity of hexacene doped with iodine

Hexacene (HEX) and derivatives such as dihydrohexacene and dihydroxyhexcane quinone were synthesized and thin films of them were prepared by the sublimation method. The structure and conductivity of the films both before and after doping with iodine were studied. The doped HEX film showed the conductivity of 3 × 10^?2 S/cm at room temperature, which was lower than expected since the conductivity of highly ordered pentacene was above 100 Ω^?1 cm^?1. The reason for the low conductivity was considered to be the disorder in molecular alignment since the HEX film showed an amorphous structure. A reversible change in the conductivity of the HEX film was observed in air and in vacuum.     

Electrochemical Intercalation of Lithium Ions into Electrolytic Vanadium Pentoxide

The discharge of thin films of Li _x V₂O₅ is described by a mathematical diffusion model. The chemical diffusion coefficient for lithium ions, estimated with the model, is equal to (1.01–2.5) × 10^–11 cm²/s. As the film thickness increases, the discharge capacity at a current of 20 A/cm² tends to the calculated limiting of 3.12 C/cm². The optimum thickness of the film electrode calculated for a discharge current of 20 A/cm² is 33.4 m and agrees satisfactorily with the experimental value.     

Paper-based all-solid-state flexible asymmetric micro-supercapacitors fabricated by a simple pencil drawing methodology

A simple and novel methodology was developed for manufacturing interdigitated asymmetric all-solid-state flexible micro-supercapacitors (MSCs) by a facile pencil drawing process followed by electrodepositing MnO₂ on one of the as-drawn graphite electrode as anode and the other as cathode.     

High‐performance Flexible Complementary Electrochromic Device Based on Plasma Modified WO3 Nano Hybrids and V2O5 Nanofilm with Low Operation Voltages

Tungsten trioxide‐poly(3,4‐ethylenedioxythiophene) (WO₃‐PEDOT) and tungsten trioxide‐polyfuran (WO₃‐PFu) were prepared by rf rotating plasma polymerization. Electrochromic hybrid thin films were fabricated onto flexible polyethylene terephthalate (PET)/ indium tin oxide (ITO) film using electron beam evaporation method. In order to deeply characterize all films, scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDS) and electrochemical impedance spectroscopy (EIS) techniques were used. The counter electrode effect on plasma modified WO₃ nano hybrids‐based electrochromic devices (ECDs) was evaluated. By incorporating flexible vanadium pentoxide (V₂O₅) film as counter electrode, complementary ECDs were constructed through combining the hybrid flexible films (WO₃‐PEDOT, WO₃‐PFu) as working electrodes, which exhibit highly efficient electrochromic performance with low voltage operation. Especially, WO₃‐PEDOT/V₂O₅‐based ECD owns a high optical modulation of 61.5 % at 750 nm driven by −1.0 V (coloration) and +1 V (bleaching) with fast response times (coloration time: 13.58 s, bleaching time: 8.07 s) and a high coloration efficiency of 527 cm² C⁻¹. This study can supply useful and efficient avenue for designing flexible complementary electrochromic device for energy‐saving flexible electronics.     

Highly enhanced thermoelectric performance of WS2 nanosheets upon embedding PEDOT:PSS

Two‐dimensional (2D) WS₂ nanosheets (NSs) as a promising thermoelectric (TE) material have gained great concern recently. The low electrical conductivity significantly limits its further development. Herein, we reported an effective method to enhance the TE performance of WS₂ NSs by combining poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS). The restacked WS₂ NSs thin film with 1T phase structure obtained by a common chemical lithium intercalation show a high Seebeck coefficient of 98 μV K^?1 and a poor electrical conductivity of 12.5 S cm^?1. The introduction of PEDOT:PSS with different contents obviously improve the electrical conductivity of WS₂ NSs thin films. Although a declining Seebeck coefficient was observed, an optimized TE power factor of 45.2 μW m^?1 k^?1 was achieved for WS₂/PEDOT:PSS composite thin film. Moreover, the as‐prepared WS₂/PEDOT:PSS thin film can be easily peeled off and transferred to other substrate leading to a more promising application. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 997–1004     

多金属氧酸盐四硫富瓦烯衍生物荷移盐超薄导电膜(英)

0IntroductionThecharge鄄transfer(CT)saltsbasedplanarπ鄄electrondonorETasaclassofmolecule鄄basedmate鄄rialshavebeenstudiedextensivelyinthepasttwentyyears,becauseoftheirmetallicconductivityandevensuperconductivity[1~6].Inrecentyears,polyoxometalateshaveatt     

Coordination Polymer Framework Based On‐Chip Micro‐Supercapacitors with AC Line‐Filtering Performance

On‐chip micro‐supercapacitors (MSCs) are important Si‐compatible power‐source backups for miniaturized electronics. Despite their tremendous advantages, current on‐chip MSCs require harsh processing conditions and typically perform like resistors when filtering ripples from alternating current (AC). Herein, we demonstrated a facile layer‐by‐layer method towards on‐chip MSCs based on an azulene‐bridged coordination polymer framework (PiCBA). Owing to the good carrier mobility (5×10⁻³ cm² V⁻¹ s⁻¹) of PiCBA, the permanent dipole moment of azulene skeleton, and ultralow band gap of PiCBA, the fabricated MSCs delivered high specific capacitances of up to 34.1 F cm⁻³ at 50 mV s⁻¹ and a high volumetric power density of 1323 W cm⁻³. Most importantly, such MCSs exhibited AC line‐filtering performance (−73° at 120 Hz) with a short resistance–capacitance constant of circa 0.83 ms.     

Conductivity enhancement of PEDOT:PSS film via sulfonic acid modification: application as transparent electrode for ITO-free polymer solar cells

3-Hydroxy-1-propanesulfonic acid(HPSA)was applied as a modification layer on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)film via spin-coating,resulting in a massive boost of the conductivity of PEDOT:PSS film,and thus the as-formed PEDOT:PSS/HPSA bilayer film was successfully used as a transparent electrode for ITO-free polymer solar cells(PSCs).Under the optimized concentration of HPSA(0.2 mol L~(-1)),the PEDOT:PSS/HPSA bilayer film has a conductivity of 1020 S cm~(-1),which is improved by about 1400 times of the pristine PEDOT:PSS film(0.7 S cm~(-1)).The sheet resistance of the PEDOT:PSS/HPSA bilayer film was 98Ωsq~(-1),and its transparency in the visible range was over 80%.Both parameters are comparable to those of ITO,enabling its suitability as the transparent electrode.According to atomic force microscopy(AFM),UV-Vis and Raman spectroscopic measurements,the conductivity enhancement was resulted from the removal of PSS moiety by methanol solvent and HPSA-induced segregation of insulating PSS chains along with the conformation transition of the conductive PEDOT chains within PEDOT:PSS.Upon applying PEDOT:PSS/HPSA bilayer film as the transparent electrode substituting ITO,the ITO-free polymer solar cells(PSCs)based on poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]:[6,6]-phenyl C71-butyric acid methyl ester(PC_(71)BM)(PCDTBT:PC_(71)BM)active layer exhibited a power conversion efficiency(PCE)of 5.52%,which is comparable to that of the traditional ITO-based devices.     

Photovoltaic properties of lead telluride thin film

Polycrystalline PbTe thin film is prepared on glass substrate at 200 °C. PbTe thin film isN-type and the carriers are electrons. The incident energy of photons, 3.4 eV, generates more electron carriers as the distance decreases which give rise to photoelectric current. The density of donorsN _d was determined to be 1.1×10²⁰ cm^?3 which is consistent with theN-type conduction of PbTe. The activation energies ofN-type PbTe thin films are 0.139, 0.139 and 0.126 eV below 60 °C which change toP-type above 60 °C. This may be due to generation of Pb vacancies in the lattice. The piezoresistivity is measured, the increase of conductivity may be due to displacements of lattice defects under applied stress.     

Nanostructured Cobalt(II) Tetracarboxyphthalocyanine Complex Supported Within the MWCNT Frameworks: Electron Transport and Charge Storage Capabilities

The electrochemical redox properties of a surface‐confined thin solid film of nanostructured cobalt(II) tetracarboxyphthalocyanine integrated with multiwalled carbon nanotube (nanoCoTCPc/MWCNT) have been investigated. This novel nanoCoTCPc/MWCNT material was characterized using SEM, TEM, zeta analysis and electrochemical methods. The nanoCoTCPc/MWCNT nanohybrid material exhibited an extra‐ordinarily high conductivity (15 mS cm^?1), which is more than an order of magnitude greater than that of the MWCNT‐SO₃H (527 µS cm^?1) and three orders of a magnitude greater than the nanoCoTCPc (4.33 µS cm^?1). The heterogeneous electron transfer rate constant decreases as follows: nanoCoTCPc/MWCNT (k_app≈19.73×10^?3 cm s^?1)>MWCNT‐SO₃H (k_app≈11.63×10^?3 cm s^?1)>nanoCoTCPc (k_app≈1.09×10^?3 cm s^?1). The energy‐storage capability was typical of pseudocapacitive behaviour; at a current density of 10 µA cm^?2, the pseudocapacitance decreases as nanoCoTCPc/MWCNT (3.71×10^?4 F cm^?2)>nanoCoTCPc (2.57×10^?4 F cm^?2)>MWCNT‐SO₃H (2.28×10^?4 F cm^?2). The new nanoCoTCPc/MWCNT nanohybrid material promises to serve as a potential material for the fabrication of thin film electrocatalysts or energy‐storage devices.     

Materials for all-solid-state thin-film rechargeable lithium batteries by sol-gel processing

A novel all-solid-state thin-film lithium battery has been fabricated by spin coating V₂O₅ and LiClO₄-SiO₂ thin films on a stainless steel substrate. The LiClO₄-SiO₂ electrolyte has been synthesized using a new sol-gel route and it has been characterized by electrochemical impedance spectroscopy. The Li⁺ ion conductivity of the spin-coated thin film thus measured is in the order of 10^–6 S/cm, at 25 °C, which is sufficient for electrolytes in such thin-film batteries. The battery shows a typical discharge capacity of about 150 μAh/mg and satisfactory cathodic efficiency and cycle-life performance. Electronic Publication     

Ionic Liquid Based Polymer Gel Electrolytes for Use with Germanium Thin Film Anodes in Lithium Ion Batteries

Thermally stable, flexible polymer gel electrolytes with high ionic conductivity are prepared by mixing the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (C₄mpyrTFSI), LiTFSI and poly(vinylidene difluoride-co-hexafluoropropylene (PVDF-HFP). FT-IR and Raman spectroscopy show that an amorphous film is obtained for high (60 %) C₄mpyrTFSI contents. Thermogravimetric analysis (TGA) confirms that the polymer gels are stable below ∼300 °C in both nitrogen and air environments. Ionic conductivity of 1.9×10⁻³ S cm⁻² at room temperature is achieved for the 60 % ionic liquid loaded gel. Germanium (Ge) anodes maintain a coulombic efficiency above 95 % after 90 cycles in potential cycling tests with the 60 % C₄mpyrTFSI polymer gel.     

Preparation and properties of rare earth (Eu, Tb, Ho) and transition metal (Co) co-doped BiFeO3 thin films

Ferroelectric (Bi_0.9 RE _0.1)(Fe_0.975Co_0.025)O_3-δ (RE = Eu, Tb and Ho) thin films were prepared on Pt(111)/Ti/SiO₂/Si(100) substrates via a chemical solution deposition method. All thin films were crystallized in a distorted rhombohedral perovskite structure confirmed by using an X-ray diffraction and a Raman scattering analyses. Compared to the pure BiFeO₃ thin film, improved electrical and ferroelectric properties were observed for the co-doped thin films. Among the thin films, the lowest leakage current density of 4.28 × 10^?5 A/cm² was measured at an applied electric field of 100 kV/cm for the (Bi_0.9Ho_0.1)(Fe_0.975Co_0.025)O_3-δ thin film. This value is approximately three orders lower than that of the pure BFO thin film. Furthermore, a large remnant polarization (2P _r) of 60.2 μC/cm² and a low coercive field (2E _c ) of 561 kV/cm at 980 kV/cm were observed from the (Bi_0.9Ho_0.1)(Fe_0.975Co_0.025)O_3-δ thin film.     

Frequency dependent ferroelectric and electrical properties of (Ho, Ni) co-doped BiFeO3 thin films

We have evaluated the ferroelectric and electrical properties of pure BiFeO₃ (BFO) and (Bi_0.9Ho_0.1)(Fe_1?xNi_x)O_3?δ (BHFN_xO, x = 0.01, 0.02, and 0.03) thin films as frequency varying from 1 to 50 kHz on Pt(111)/Ti/SiO₂/Si(100) substrates by using a chemical solution deposition method. With the frequency from 1 to 10 kHz, the decrease of remnant polarization (2P _r ) of the BHFN_0.02O thin film was about 27 %, from 26 to 19 μC/cm², which is one half lower than those of the BHFN_xO (x = 0.01 and 0.03) thin films. Otherwise, the variation of the coercive electric field (2E _c ) was relatively small, which were 16, 11 and 3 % for the BHFN_xO (x = 0.01, 0.02, and 0.03) thin films. The remnant polarization (2P _r ) and the coercive electric field (2E _c ) values of the BHFN_0.02O thin film show the dependence of measurement frequency and it has been fairly saturated about 30 kHz. Also, the leakage current density of the co-doped BHFN_0.02O thin film showed three orders lower than that of the pure BFO, 2.14 × 10^?6 Å/cm² at 100 kV/cm.     

Sol-gel derived (LiCl)2-Al2O3-SiO2 thin film solid electrolyte

(LiCl)₂-Al₂O₃-SiO₂ thin film solid electrolyte was prepared by a sol-gel process with a spin coating technique. The thin film was studied by X-ray photoelectron spectroscopy (XPS) and ac impedance. The ionic conductivity of the solid electrolyte film is comparable to that of the bulk xerogel. The highest conductivity measured by ac impedance is 2.5×10^–4 S·cm^–1 at 300°C with E_a=0.75 eV.     

溶液法制备氧化锌半导体薄膜及其顶栅极晶体管器件

采用旋涂法用浓度分别为0.05,0.10和0.25 mol·L^-1的氧化锌前躯体溶液制备了氧化锌薄膜,并且制备了基于氧化锌多层膜的顶栅极晶体管器件,其中以利用光刻工艺刻蚀的氧化铟锡为源漏电极。通过原子力显微镜(AFM)和X-射线衍射(XRD)分别表征了薄膜的形貌以及结晶情况,并且讨论了前躯体的浓度顺序对氧化锌多层膜的影响。按照浓度从大到小的顺序依次旋涂前躯体溶液制备的氧化锌薄膜表现出了较高的载流子迁移率(7.1×10^-3 cm²·V^-1·s^-1),而按照浓度从小到大的顺序依次旋涂前躯体溶液制备的氧化锌薄膜的载流子迁移率为5.2×10^-3 cm²·V^-1·s^-1。文中通过对两种多层薄膜的形貌和结晶性能的分析表明影响顶栅极薄膜晶体管性能的主要因素是薄膜的粗糙度。平整的薄膜有利于形成较好的半导体层/绝缘层接触界面,从而有利于提高器件的载流子迁移率。     

The Application of a Y-Modified Lanthanum Zirconate Flexible Thin Film for a High-Performance Flexible Supercapacitor

With the rapid development of wearable electronics devices, there is increasing demand for the development of new flexible energy storage devices with high security, and this has become a hot research topic. Although flexible supercapacitors are considered to be high-performance energy-storage equipment because of their fast charging/discharging ability, long cycle life, good reliability, wide operating temperature range, and so on, there are still many drawbacks that need to be overcome. Herein, the La₂Zr₂O₇ (LZO) thin film is synthesized as a new energy-storage material by using a facile electrospinning method and calcination at low temperature. In addition, the mechanism of producing the flexibility of this film is determined by TG, IR, and XRD analyses. As previous studies have suggested that the charge storage of the LZO film can be attributed to the mechanism of oxygen intercalation, the Y element is doped into the LZO film to increase the concentration of oxygen vacancies. The changes in structural and electrochemical properties of La₂Y_xZr_2−xO₃ (0≤x≤0.5) nanofibers (LNF-x) with increasing Y content are studied carefully to obtain the best doping sample. The LNF-0.1 sample shows the highest areal capacitance of 605.3 mF cm⁻² at 2 mA cm⁻², so a symmetrical flexible device is fabricated with LNF-0.1 electrodes. This device has a high energy density (76.7 μW h cm⁻² at 2 mW cm⁻²), good cycling stability, and excellent mechanical flexibility. This study thus provides a new research trend for portable and wearable electronics.