Electrical properties of Sm-doped bismuth titanate thin films prepared on Si (100) by metalorganic decomposition

Samarium-doped bismuth titanate Bi_4−xSm_xTi₃O₁₂ (BSmT)] thin films have been grown on n-type Si (100) substrates using metalorganic decomposition and subsequent annealing at 700 °C for 1 h. X-ray diffraction analysis showed layered perovskite structures with a single phase in the films. The current-voltage characteristics displayed ohmic conductivity in the lower voltage range and space-charge-limited conductivity in the higher voltage range. The capacitance-voltage characteristics of Au/BSmT/Si (100) exhibited hysteresis loops due to the ferroelectricity and did not show large carrier injections. The fixed charge density and the surface state density of BSmT films on Si substrate were calculated to be in the range of 10¹¹ cm⁻² and 10¹² cm⁻² eV⁻¹, respectively.