ITO-TiO2 Heterojunctions on Glass Substrates for Photocatalytic Gold Growth Along Pattern Edges

This study investigates the effects of varying indium tin oxide (ITO) layer thicknesses and the patterning of the ITO layer on the growth of metallic gold (Au) nano- and microstructures on titanium dioxide (TiO₂) templates. The ITO-TiO₂ heterojunction serves to collect photogenerated electrons in the ITO sublayer, facilitating their transport to the pattern edges and concentrating photocatalytic activity at these edges. Six template types were fabricated on glass substrates, with systematic variations in ITO thickness (0, 3, 6, 10, and 30 nm) and different ITO patterning methods (either continuous or patterned with the TiO₂ layer). Photocatalytic gold growth was carried out on each of the substrates, and morphological analysis was conducted using scanning electron microscopy (SEM). Results showed that a 6 nm ITO layer beneath a 70 nm TiO₂ layer yielded the most uniform gold lines, characterized by 3D flower-shaped structures and enhanced edge growth. Conductance measurements indicated a value of 23 mS, suggesting potential applications in bio-inspired electronics. These findings provide insights into optimizing gold structure growth for advanced neuromorphic devices.