Au nanopatterns on glass substrate using block copolymer and their applications in transparent conducting electrode

Abstract

High density Au nanostructures were fabricated using polystyrene-block-polymethylmethacrylate (PS-b-PMMA) copolymer on glass substrate for the preparation of electrode materials with good stability, high transparency and excellent conductivity. A 1wt.% polymer solution in toluene was spin coated on glass substrate. Samples were baked for 48h at 200°C with a continuous flow of Ar. Patterned polymer film was obtained by removing the PMMA region through exposing ultraviolet irradiation and rinsing in acetic acid. Au thin films with several thicknesses were then deposited onto the patterned glass substrates by thermal evaporation or sputtering. Removing PS cylinders by sonicating in acetone resulted in Au nanopattern on glass substrates. The connecting gold film acts as conductor while the holes allow light pass through it and helps to be transparent. The transmittance with Au film thickness of 7nm and 4nm was found to be about 63% and 70%, respectively. The resistivity was in the range 10−5Ωcm–10−6Ωcm which is comparable with ITO (10−3Ωcm–10−4Ωcm).