Optical and transport properties of LaTi1−xMx(O,N)3±δ (x=0; 0.1, M=Nb5+, W6+) thin films prepared by plasma ammonolysis

• A new synthesis method for oxynitride thin films is presented.
• The bandgap is tuneable by cationic co-substitution of W6+ and Nb5+ for Ti4+ in LaTiO2N.
• Cationic co-substitution with W6+ and Nb5+ increased the electrical conductivity.

Oxynitride thin films of composition LaTi1−xMx(O,N)3±δ with x=0; 0.1 and M=Nb5+, W6+ were prepared by nitridation via microwave-induced plasma (MIP) ammonolysis, which allowed keeping the nitridation time short (16 min). The higher possible oxidation states of the B-site substituents (Nb5+, W6+) with respect to Ti4+ caused higher N content for LaTi0.9Nb0.1(O,N)3±δ and LaTi0.9W0.1(O,N)3±δ compared to LaTiO2N due to charge-compensation. XPS O 1s and N 1s core level and valence band spectra evidenced for increasing N content in the order LaTiO2N

The synthesis of LaTi1−xMx(O,N)3±δ (x=0; 0.1, M=Nb5+, W6+) thin films by microwave-induced plasma ammonolysis is described and changes of their optical and transport properties upon B-site substitution are discussed.Figure optionsDownload as PowerPoint slide