Xiujing Lin

Copper Mesh Templated by Breath-Figure Polymer Films as Flexible Transparent Electrodes for Organic Photovoltaic Devices

UNLABELLED Metal mesh is a significant candidate of flexible transparent electrodes to substitute the current state-of-the-art material indium tin oxide (ITO) for future flexible electronics. However, there remains a challenge to fabricate metal mesh with order patterns by a bottom-up approach. In this work, high-quality Cu mesh transparent electrodes with ordered pore arrays are prepared by using breath-figure polymer films as template. The optimal Cu mesh films present a sheet resistance of 28.7 Ω·sq(-1) at a transparency of 83.5%. The work function of Cu mesh electrode is tuned from 4.6 to 5.1 eV by Ag deposition and the following short-time UV-ozone treatment, matching well with the PEDOT PSS (5.2 eV) hole extraction layer. The modified Cu mesh electrodes show remarkable potential as a substitute of ITO/PET in the flexible OPV and OLED devices. The OPV cells constructed on our Cu mesh electrodes present a similar power conversion efficiency of 2.04% as those on ITO/PET electrodes. The flexible OLED prototype devices can achieve a brightness of 10 000 cd at an operation voltage of 8 V.

Self-propelled manganese oxide-based catalytic micromotors for drug delivery

A manganese oxide-based catalytic tubular micromotor (PEDOT/MnO2) is described that displays effective autonomous motion in hydrogen peroxide with high speed (318.80 µm s−1) and can operate in very low levels of fuel, down to 0.4%. The polymer bilayer micromotor also exhibits efficient locomotion in different biological media including bovine serum albumin and bovine serum. Moreover, the micromotor is applied to deliver a chemotherapeutic anticancer drug, camptothecin, using electrostatic interactions, offering considerable potential for diverse clinical and biomedical applications such as drug delivery for theranostic microsystems.

Hierarchical dispersed multi-phase nickel cobalt oxide mesoporous thorn microspheres as superior rate anode materials for lithium ion batteries

Hierarchical nickel cobalt oxide (NCO) microspheres comprised of nanoscale mesoporous thorn arrays are developed as superior rate high capacity anodes in this work, i.e. 1063.3 and 860 mA h g−1 at 180 and 4500 mA g−1, respectively. Stoichiometric urea serves as a self-template to favor the self-assembly of well-organized NiCo(OH)2CO3 thorn microsphere precursors under an optimized hydrothermal reaction. The dispersed multi-phase hybrid crystal structure and the favorable specific surface area obtained during the controlled pyrolysis of NiCo(OH)2CO3 microspheres markedly promote the cyclic stability of the single phase Ni1.5Co1.5O4.

High rate Li-ion storage properties of MOF-carbonized derivatives coated on MnO nanowires

Recently, metal–organic framework (MOF) derived porous carbon-based composites have become one of the most advanced electrode materials for high performance energy storage systems. In this work, zeolitic imidazolate framework (ZIF) types of MOF strung by MnO2 NWs, forming an interesting structure like Chinese candied hawthorn fruit on a stick, are used as precursors to prepare C/Co-coated MnO nanowires (C/Co-MnO NWs). It is interesting and exciting to observe that the simultaneously formed carbon coating derived from the ZIFs significantly promotes the cyclic and rate performances of manganese oxide because of the synergistic effect of the highly conductive uniform carbon coating and the high capacity contribution from the MnO NWs. The obtained C/Co-MnO NWs could deliver 848.4 and 718 mA h g−1 at 500 and 5000 mA g−1 after 40 charge/discharge cycles, respectively, which is superior to other reported MOF-derived nanostructured materials, and makes it a very promising candidate anode material for future high-power lithium ion batteries.

Industrially weavable metal/cotton yarn air electrodes for highly flexible and stable wire-shaped Li–O2 batteries

Li–O2 batteries feature extremely high energy density, making their wire-shaped devices a promising candidate for wearable energy-storage application. However, it is a major challenge to explore industrially feasible electrodes for this type of linear batteries. Herein, for the first time, we have demonstrated an effective strategy to fabricate a feasible electrode on a large scale by dyeing industrially weavable and highly conductive metal/cotton yarns with the active material ink, RuO2-coated nitrogen-doped carbon nanotube (CNT). The obtained wire-shaped Li–O2 battery exhibits a high discharge capacity of 1981 mA h gcarbon−1 at a current density of 320 mA gcarbon−1 and could stably work beyond 100 cycles (more than 600 hours) without obvious degradation, even under bending conditions. The new freestanding type electrode will represent a critical step towards the production and practical application of flexible Li–O2 batteries.

Bimetal-organic-framework derived CoTiO 3 mesoporous micro-prisms anode for superior stable power sodium ion batteries

Durability, rate capability, capacity and tap density are paramount performance metrics for promising anode materials, especially for sodium ion batteries. Herein, a carbon free mesoporous CoTiO3 micro-prism with a high tap density (1.8 g cm−3) is newly developed by using a novel Co-Ti-bimetal organic framework (BMOF) as precursor. It is also interesting to find that the Co-Ti-BMOF derived carbon-free mesoporous CoTiO3 micro-prisms deliver a superior stable and more powerful Na+ storage than other similar reported titania, titanate and their carbon composites. Its achieved capacity retention ratio for 2,000 cycles is up to 90.1% at 5 A g−1.摘要负极材料的循环、 倍率、 容量和堆积密度是评价钠离子电池性能的关键指标. 为此本工作开发了一种新型的钴-钛双金属-有机框架结构材料并以其作为前躯体衍生制备了具有1.8 g cm−3高堆积密度的无碳介孔钛酸钴微米棱柱状材料. 作为钠离子电池负极材料该种材料展示了超高稳定性同时拥有比其他类似的钛氧化物、 钛酸盐及其碳基复合材料更优异的倍率性能, 其在5 A g−1的电流密度下循环2000圈后容量保持率高达90.1%.

Full-solution processed all-nanowire flexible and transparent ultraviolet photodetectors

Sandwich metal–semiconductor–metal (MSM) structured ultraviolet (UV) photodetectors have attracted much attention in wearable and implantable electronics due to their large UV adsorption area and high compatibility for large-scale production. However, there is a lack of an effective approach to fabricate highly transparent and flexible sandwich MSM structured devices. In this work, we develop a full-solution process to fabricate a flexible and transparent sandwich MSM structured device based on vertically aligned zinc oxide nanowires (ZnO NW) arrays. To achieve high flexibility and transparency, silver nanowires (Ag NW) networks were introduced as both bottom and top electrodes, and especially as substrates for vertically aligned ZnO NW array growth. Such a Ag NW/ZnO NW/Ag NW sandwich MSM structured device shows a high transparency of 75.0% and excellent mechanical stability. This UV photodetector exhibits a low operation voltage of 0.5 V, a high photocurrent/dark current ratio of 9756 and fast photoresponse properties with a rise time of 1.83 s and a decay time of 1.75 s, demonstrating great potential for low cost and large area wearable electronics applications.

Air-stable, transparent flexible ambipolar organic thin film transistors based on CuPc-F16CuPc bi-channel structure

We report the fabrication of air-stable, transparent flexible ambipolar organic thin film transistors based on CuPc and F16CuPc bi-channel films deposited under 10−1 Pa, by using graphene gate electrode, fluoropolymer Cytop dielectric layer, and Au source/drain electrodes on polyethylene terephthalate substrates. The devices show outstanding air-stability and high optical transparency of above 75% with electron and hole mobilities up to 0.031 and 0.029 cm2/V·s, respectively. The excellent ambipolar performance, along with the outstanding air-stability and high optical transparency, make CuPc-F16CuPc bi-channel transistors as a promising candidate for organic integrated circuits.We report the fabrication of air-stable, transparent flexible ambipolar organic thin film transistors based on CuPc and F16CuPc bi-channel films deposited under 10−1 Pa, by using graphene gate electrode, fluoropolymer Cytop dielectric layer, and Au source/drain electrodes on polyethylene terephthalate substrates. The devices show outstanding air-stability and high optical transparency of above 75% with electron and hole mobilities up to 0.031 and 0.029 cm2/V·s, respectively. The excellent ambipolar performance, along with the outstanding air-stability and high optical transparency, make CuPc-F16CuPc bi-channel transistors as a promising candidate for organic integrated circuits.