Junction-free Flat Copper Nanofiber Network-based Transparent Heater with High Transparency, High Conductivity, and High Temperature

Abstract

Transparent conducting electrodes (TCE) are widely used in a variety of applications including displays, light-emitting diodes (LEDS), and solar cells. An important factor in TCE design is active control of the sheet resistance and transparency; as these are inversely proportional, it is essential to develop a technology that can maintain high transparency, while actively controlling sheet resistance, for a range of applications. Here, a nanofiber network was fabricated based on direct electrospinning onto a three-dimensional (3-D) complex substrate; flat metal electrodes without junction resistance were produced using heat treatment and electroless deposition. The fabricated transparent electrode exhibited a transparency of over 90% over the entire visible light range and a sheet resistance of 4.9 ohms/sq. Adhesion between the electrode and substrate was superior to other electrospinning-based transparent electrodes. The performance of the transparent electrode was verified by measurements taken while using the electrode as a heater; a maximum temperature of 210 °C was achieved. The proposed copper nanofiber-based heater electrode offers the advantages of transparency as well as application to complex 3-D surfaces.

Reduced Graphene Oxide Conformally Wrapped Silver Nanowire Networks for Flexible Transparent Heating and Electromagnetic Interference Shielding

“…To emphasize the good optoelectronic performance of the AgNW@rGO networks, the sheet resistance values as a function of transmittance at 550 nm are listed for our AgNW@rGO networks and for other landmark TCs reported in the literature, as shown in Figure g. At the same transmittance, the sheet resistance of the AgNW@rGO networks is lower than that of graphene, Ag/CuNW–graphene/rGO/CNTs composite films, ,,,− Ag/CuNW networks, ,,, CuNW@graphene network, CuNW@rGO network, and ITO film and is comparable with the values of the thermally evaporated Au nanotrough–graphene composite film and thermally annealed Ag nanofiber network …”

“…(g) Plot of sheet resistance versus transmittance at 550 nm for the AgNW@rGO networks. The performances of previously reported TCs are shown for comparison. − ,,,− ,− …”

Self-assembly, alignment, and patterning of metal nanowires

“…The self-assembly strategies of MNWs, such as the coffee-ring effect and ice template methods, are first described to show their advantages of low cost, easy operation, and flexible controllability. 32,34,35,45–51 Subsequently, we discuss the methods to realize the alignment of MNWs, including the classical Langmuir–Blodgett (LB) technique, 30,52–59 assembly in an electric and magnetic field, 60–72 bubble blowing technique, 73,74 electrospinning, 75–81 electrohydrodynamic (EHD) jet printing, 12,82–85 and recently developed assembly at air/solid–liquid interfaces like the Marangoni flow-assisted float assembly. 28,29,86–97 The following section focuses on a variety of patterning approaches to construct high-performance transparent, flexible, and/or stretchable electrodes (SEs), which can be divided into top-down technical routes, including traditional photolithography, adhesion difference-based selective removal, 37 novel Plateau–Rayleigh instability-induced patterning, 98 etc.…”

Highly-robust, solution-processed flexible transparent electrodes with a junction-free electrospun nanofiber network

“…In this study, we developed a new method for fabricating two-dimensional (2D) transparent electrodes on flexible polymer films using electrospinning and copper electroless deposition. 31 A random network was formed by electrospinning a polymer solution containing palladium ions onto a transparent polyimide (PI) film. The electrospun palladium-embedded polymer network was heat-treated to form a seed layer for the electrode, and a subsequent copper nanofiber network was fabricated by copper electroless deposition.…”