Adjusting the viscosity of silver nanowire ink for promoting the uniformity and conductivity of transparent electrode

In this work, we report a suitable thickening agent (cellulose nanofibril: CNF) to promote the uniformity and conductivity of silver nanowire (AgNW) transparent electrode by increasing the viscosity of AgNW ink. CNF exhibits fascinating characteristics. First, it doesn’t lower the conductivity and transmittance of film. Second, it greatly promotes the dispersity degree of AgNW in ink. Third, it doesn’t affect the ink wetting. Fourth, it increases the ink viscosity and slows the ink flow to solve the problems of disorderly ink flow and ink shrinkage. Finally, it makes the wet film dry uniformly. Hence, CNF greatly promotes the distribution uniformity of AgNW in film. As a result, with the same amount of AgNW, more conductive paths can be constructed in AgNW-CNF film to endow the film with much higher conductivity. Specifically, the sheet resistance, variation coefficient of sheet resistance, transmittance of AgNW film are 38.7 × 10 3 Ω/sq, 40.49%, 90.29%, while those of AgNW-CNF film are 77.5 Ω/sq, 1.59%, 91.89%. Meanwhile, although CNF doesn’t promote the adhesion force, it really greatly promotes the erasion difficulty of AgNW from the substrate. These results demonstrate that CNF and our strategy are effective. In transparent-electrode field, such suitable thickening agent is rare at present.