Pulsed laser deposition of bismuth telluride thin film and annealing effects

Pulsed laser deposition method was used to prepare Bi2Te3 thermoelectric thin films on a soda lime glass substrate at room temperature. Surface morphology of Bi2Te3 thin films was studied by AFM (atomic force microscopy) images. The influence of thermal annealing in vacuum condition on microstructure and surface morphology of films was investigated in wide range of temperature. The results demonstrate that annealing induces a transition from amorphous to polycrystalline structures and increases electrical conductivity. X-ray diffraction analysis proves that the film annealed at 300 °C for 120 min appears in large grain size polycrystalline structure but film annealed at 400 °C in the same condition has a preformed crystal growth texture in (006) direction.