Evaluation of reliability and development of auxiliary materials to enhance the performance of silver nanowire transparent electrodes

Abstract

Materials used for transparent electrodes require both high electrical conductivity and high light transmittance, which are mutually contradictory properties, and thus the kinds of materials that meet the conditions are extremely rare. To date, most widely used transparent electrode materials are doped, oxide based semiconductor materials such as indium tin oxide. However, with recent increase in demand and interests for flexible devices, development of new materials with sufficient mechanical flexibility is needed since the oxide based materials are highly brittle that can generate cracks even at a small strain, which would result in failure of the transparent electrode. On the other hand, the performance of transparent electrodes using one-dimensional materials such as silver nanowires is comparable to that of indium tin oxide and exhibits greatly improved mechanical reliability. However, there are challenges still remaining for silver nanowire based transparent electrodes such as thermal and chemical instability of nanomaterials, low adhesion with substrates, low charge collection and injection ability owing to its network geometry. In chapters 2 and 3, studies on overcoming such problems of silver nanowire based transparent electrodes are discussed by introducing a solution-processed auxiliary transparent conducting materials in the form of RGO (Reduced Graphene Oxide)/Ag nanowire composite as well as solution processed ZnO/Ag nanowire composite which greatly minimize the disadvantages of silver nanowire electrodes and also improve its electrical and optical performances. In chapter 4, we discuss the bending fatigue response of silver nanowire network via monitoring resistance in-situ during bending cycles and compare the behavior to that of conventional metal thin films that is expected to be useful for industrial guidelines in assessing the reliability of Ag nanowire electrode in various devices such.