Pulsed Laser Deposition of Titanium Sulfide Films from TiS2 Target under CS2 Pressure and their Thermoelectric Properties

The pulsed laser deposition of titanium sulfide films was investigated in order to develop new thermoelectric materials. The rutile-type TiO2 powder was first sulfurized with carbon disulfide (CS2) gas. After the sulfurization at 1023 K for 14 h, the resultant powder consisted entirely of the CdI2-type TiS2 phase. The TiS2 target was fabricated by pressing the TiS2 powder under a uniaxial pressure of 20 MPa. The films were prepared on fused quartz substrates by the pulsed laser deposition from the TiS2 target under CS2 pressure. The effects of the CS2 pressure and substrate temperature on the microstructure and composition were investigated. When the film was prepared at room temperature under CS2 pressure of 1.33 Pa, the composition of the film was found to be close to the target composition. The room-temperature electrical resistivity and Seebeck coefficient of this film are 63 μΩ•m and -42 μV/K, respectively.