Study of Brush-Painted Ag Nanowire Network on Flexible Invar Metal Substrate for Curved Thin Film Heater

Abstract

The objective of this study was to determine the characteristics of brush-painted Ag nanowires (NW) network electrode on a SiO2 coated invar substrate for high performance curved thin film heaters (TFHs). To avoid influence of a conductive invar metal foil substrate, thin SiO2 film was deposited on an invar substrate as an insulating layer. We measured sheet resistance, optical reflectance, and surface morphology of Ag NWs/SiO2/invar as a function of the number of brush painting from one to four times. Optimized brush-painted Ag NWs network on a SiO2/invar substrate showed a low sheet resistance 38.52 Ω/square, which was acceptable for fabrication of curved TFHs. Based on a lab-made bending and fatigue tester, critical radius of the optimized Ag NWs/SiO2/invar electrode was found to be 6 mm. It demonstrated superior repeated flexibility of an Ag NW/SiO2/invar substrate. Furthermore, we demonstrated the feasibility of using a brush-painted Ag NW/SiO2/invar substrate as an electrode for curved TFHs. These curved TFHs fabricated on an Ag NW/SiO2/invar substrate showed rapid heating properties and high saturation temperature even at low applied voltage due to low resistivity of Ag NW network. This indicates that a brush-painted Ag NW/SiO2/invar substrate is a promising flexible electrode and substrate for high performance curved TFHs.

Solution-Processed Multistacked Tin-Doped Indium Oxide Nanoparticle Conductors for Cost-Effective Thin Film Heaters

“…The quantity of heat, Q contains that c, m, and dT correspond to the specific heat capacity, mass, and amount of temperature change, respectively; Q conv and Q radi are the convective and radiative power losses, respectively. Q conv and Q radi have the following relationship: 6,17,68…”

Thermally-evaporated C60/Ag/C60 multilayer electrodes for semi-transparent perovskite photovoltaics and thin film heaters

“…The high saturation temperature of the CACbased TFHs with a lower sheet resistance indicates that electrical energy at the electrode is effectively converted to Joule heating. By Joule's law, the sheet resistance of TCE for TFHs can be correlated with the generated heat [21,51,52]. The power (P) supplied to the TFHs during the heating time (t) generated heat (∆Q g ): Here, V is the DC voltage between electrodes, R is the resistance of the TFHs, and Q conv is the convective heat.…”

“…Since the electrical and optical characteristics of the transparent electrodes significantly affect the performance of the TFHs, such as the thermal response time and saturation temperature, it is essential to ensure high-performance transparent and flexible electrodes [1,16]. Various types of TCEs, including metal grid films, metal nanowires, conducting polymer, carbon nanotubes, and graphene, have been commonly used in photovoltaics, TFHs, and optoelectronic devices [17][18][19][20][21][22][23]. However, unlike sputtered TCO cathodes, solutionprocessed or transferred TCE electrodes cannot be applied to fabricate large functional windows due to their complicated processes and difficulty in coating a large area.…”

Highly flexible Ag nanowire network covered by a graphene oxide nanosheet for high-performance flexible electronics and anti-bacterial applications

“…An AgNWs film with an irregularly connected network has been applied in flexible electronics and wearable devices due to its high conductivity, low sheet resistance, good flexibility and simple solution-based coating process [44][45][46]. It is possible to produce a cost-effective AgNWs FTCE because it can be printed by spin coating [47,48], bar coating [49], slot die coating [7,50], brush painting [51], and spray coating [52] at room temperature. However, a reduction in the AgNW concentration in ink for the purpose of confirming high transmittance resulted in a reduction in the inter-link connectivity of the AgNWs and increased the sheet resistance.…”