Simultaneous Enhancement in Visible Transparency and Electrical Conductivity via the Physicochemical Alterations of Ultrathin-Silver-Film-Based Transparent Electrodes

A methodology for the simultaneous modulation of the chemical and physical states of an amorphous TiOx layer surface and its impact on the subsequent deposition of a polycrystalline Ag layer are presented. The smoothened TiOx layer surface comprising chemically altered, oxygen-deficient states serves as a nucleating platform for Ag deposition, facilitating a marked increase (∼75%) in the nucleation number density, which strongly enhances the wettability of ultrathin Ag layers. The physically smoothened TiOx/Ag interface further reduces the optical and electrical losses. When the proposed methodology is applied to TiOx/Ag/ZnO transparent conductive electrodes (TCEs), exceptional TCE properties are yielded owing to the simultaneous improvement in visible transparency and electrical conductivity; specifically, a record-high 0.22 Ω-1 Haacke figure of merit is realized. TCEs are prepared on flexible substrates to verify their applicability as stand-alone flexible transparent heaters and as integrated heaters within electrochromic devices to enhance color-switching reactions.