Study of flexible metal nanowire based transparent electrode and ultralight, high strength 3D conductor

Abstract

In this study, we suggest to fabricate 2D flexible transparent electrode and 3D high strength lightweight material based on silver nanowire having unique mechanical, electrical and optical properties. Ag nanowire based transparent electrode was introduced to replacing ITO for display and solar cell application by using high optical transmittance from void space between nanowire network and high electrical conductivity from material of silver itself. Haze reduction of Au coated Ag nanowire transparent electrode was studied in chapter 2 for clear image of display application. This work provided results ranging from synthesis, characterization, analysis of the electrical and optical properties, as well as FDTD simulations to provide further insights to the cause for the haze reduction as a result of Au coating. Ag nanowire with PEDOT:PSS transparent electrode also studied in chaper 3 for CIGS solar cell with all solution processed, low cost, scalable method. Thin PEDOT:PSS conducting polymer layer was deposited on top of the Ag nanowire network to function as a filler for the empty space for high efficiency of electron collection. Here we provide full experimental studies that range from the electrode materials design consisting of the Ag nanowire network and conducting polymer hybrid and the application of the electrode to CIGS PV for high efficiency. Ag nanowire reinforced ultralight 3D porous composite with high strength was introduced in chapter 4 by using high porosity of 3D network structure consist of Ag nanowire and cellulose nanofibers(CNF). Higher mechanical properties of Ag nanowire than bulk material due to size effect also contribute to fabricate porous material with high strength. A one step process of uniaxial freeze drying with a solution containing Ag nanowires and CNF can be fabricated an oriented porous 3D structure. Strength of the 3D porous composite was studied as a function of pore direction and the amount of Ag nanowires embedded in the wall of CNF.