Unconventional upright layer orientation and considerable enhancement of proton-electron conductivity in Dion-Jacobson perovskite thin films

Excimer-laser-assisted metal organic deposition is a straightforward process for growing uniaxially oriented Dion-Jacobson perovskite thin films. We have confirmed that on amorphous glass substrates, Dion-Jacobson phases normally crystallize and become oriented with layer-stacking ordering, for example, in RbLa 2 Ti 2 NbO 10 and RbLaNb 2 O 7 thin films under KrF laser irradiation. Here, we observed a unique orientation in RbCa 2 Nb 3 O 10 thin films, where almost perfect upright layered structures were realized on amorphous glass substrates. The precursor RbCa 2 Nb 3 O 10 thin film crystallized in uniaxial (100)-orientation under KrF laser irradiation with a fluence above 100 mJ cm −2 and with a preference for (100)- and (001)-orientations below 100 mJ cm −2 . The obtained (100)-oriented RbCa 2 Nb 3 O 10 thin films showed an extremely high proton-electron conductivity of 4.9 × 10 −2 S cm −1 at 400 °C. Excimer-laser-assisted metal organic deposition is a straightforward process for growing uniaxially oriented Dion-Jacobson perovskite thin films.