Millimeter-Sized Single-Crystalline Anatase Nb-Doped TiO₂ Membranes Exhibiting High Electrical Conduction and Transparency

High Resolution Image Download MS PowerPoint Slide Nb-doped TiO 2 (TNO) is a transparent conducting electrode, contributing to transparent electronics and bioelectronics. Using a TNO membrane, we can fabricate transparent, flexible, and removable electrode patches and wires. However, highly conducting TNO membranes cannot be easily fabricated because of crack formation originating due to the large lattice mismatch between the sacrificial layer and TNO. Herein, La 0.7 Sr 0.3 MnO 3 was used as a sacrificial layer to reduce the lattice mismatch with TNO, and TNO epitaxial thin films were grown on a SrTiO 3 single-crystal substrate using the sacrificial layer. Although La 0.7 Sr 0.3 MnO 3 was insoluble in water but soluble in acid, fewer cracks were formed in the millimeter-sized TNO membrane because of the chemical resistance of TNO to most acids and bases. Consequently, the TNO membrane exhibited high crystallinity and electrical conductivity, similar to those of TNO epitaxial thin films.