Growth of c-Axis-Oriented BiCuSeO Thin Films Directly on Si Wafers

Single-phase, c -axis-oriented BiCuSeO thin films have been directly grown on the commercial silicon (001) wafers without any surface pretreatment by using pulsed laser deposition. X-ray diffraction pole figure confirms that the film does not have any ab- plane texture, whereas cross-sectional transmission electron microscopy shows good crystallinity of the film even if there exists an amorphous native oxide layer on the wafers surface. At room temperature, the resistivity of the film is about 14 mΩ cm, which is much lower than that reported for corresponding single crystals as well as polycrystalline bulks. This work demonstrates the possibility of using the available state-of-the-art silicon processing techniques to create BiCuSeO-based thin-film thermoelectric devices.