Figure 4

Preparation of copper electrodes using the nanopaste and characterization of the resulting electrodes. (a) A schematic illustration of the preparation of copper electrodes using the present copper nanopaste; (b) SEM images of the copper electrodes made from the nanopaste on a glass substrate and pressureless sintered at (i) 180 °C, (ii) 200 °C, (iii) 230 °C, and (iv) 260 °C under an N2 atmosphere for 30 min.