  The oxide-metal-oxide architecture is a promising approach for the
development of the high-performance indium-free transparent electrode (TE),
which is a key component of various optoelectronic applications such as solar
cells, organic LEDs, and touchscreen panels. Here in this work, we have shown
high-performance TE consisting of TiO2/Ag/TiO2 (TAT), with the incorporation of
a copper seed layer. The seed layer increases the wettability and improves the
adhesion of deposited Ag film on the bottom TiO2 layer. Before the experimental
realization, optical modeling is performed by using MATLAB code based on the
transfer matrix method. The optimum thickness obtained from the simulation is
30 nm for both undercoat and overcoat TiO2 with the average transmittance in
the visible region >85% with the Ag thickness of 9nm. With inputs from the
optical modeling, TEs were experimentally realized with and without the Cu seed
layer. It has been found that the TE with an additional sputtered Cu (1 nm)
seed layer is essential for the smooth growth of silver film and shows better
electro-optical performance (sheet resistance < 10 and average transmittance in
the visible spectral range > 80%) than TAT-TE without any seed layer. The
electro-optical and morphological properties of the TiO2/Cu/Ag/TiO2 structure
make it suitable for optoelectronic applications.
