Fig. 1

Ba_1−xLa_xSnO₃ (BLSO) films grown on (001)-oriented MgAl₂O₄ with an MgO template layer to fabricate transparent conductors with electromagnetic shielding capabilities (TC-EMS). For convenience, we use the simpler form of \({(100\times x)\mathrm{\%}-\mathrm{BLSO}}_{\mathrm{substrate}}^{\mathrm{template\,layer}}\). a The sheet resistance of \(5\%-{\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}^{\mathrm{MgO}}\) is lower by three orders of magnitude than that of \({\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}\), and thus comparable to that of single-crystalline \({\mathrm{BLSO}}_{{\mathrm{SrTiO}}_{3}}\). b The \(5\%-{\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}^{\mathrm{MgO}}\) exhibits high transmittance (> 85%) in the visible region; the “DGIST” logo can be seen through the \(5\%-{\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}^{\mathrm{MgO}}\). The transmittance in the infrared region was suppressed by the free electron response. The fundamental absorption edge of \(5\%-{\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}^{\mathrm{MgO}}\), at which the transmittance drops sharply at ultraviolet wavelengths, lies at a shorter wavelength of ~ 300 nm than ~ 400 nm of \({\mathrm{BLSO}}_{{\mathrm{SrTiO}}_{3}}\). The dashed lines indicate the transmittances of the MgAl₂O₄ and SrTiO₃ substrates. c The \(5\%-{\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}^{\mathrm{MgO}}\) shielding effectiveness (SE) is ~ 25.9 dB at 10 GHz. SE_A and SE_R represent the wave transmitted through the film and MgAl₂O₄ substrate, and the wave reflected from the BLSO film, respectively. The films exhibit an SE_A of ~ 21.0 dB, which is larger than the SE_R of ~ 4.9 dB at 10 GHz. d The \(5\%-{\mathrm{BLSO}}_{{\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}}^{\mathrm{MgO}}\) thus shows superior conductivity, transmittance, and SE than the potential TC-EMS materials Sn-doped In₂O₃ (ITO) [10] and SrMoO₃. [12]