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We performed the electrical resistivity and thermoelectric power measurements of the polycrystalline La0.8Ti0.2OBi(S1-xSex)2. The electrical resistivity of La0.8Ti0.2OBi(S0.7Se0.3)2 at room temperature dramatically decreases, and the temperature dependence shows metallic-like behavior. From the electrical resistivity, superconductivity was not observed in La0.8Ti0.2OBi(S1-xSex)2 above 2.8 K. The value of thermoelectric power S(300 K) of La0.8Ti0.2OBiSSe was about -65 μV/K, which is comparable to that of the polycrystalline LaOBiS2. The value of S(300 K) of La0.8Ti0.2OBiS2 was about -115 μV/K. These power factors are relatively smaller than that of the polycrystalline LaOBiSSe.

Electrical resistivity of LaO0.5F0.5Bi(S0.9Se0.1)2 have been measured at a temperature range of 2.8 ∼ 300 K by applying several hydrostatic pressures. Pressure-induced superconducting phase was observed above a pressure P of 0.85 GPa and Tc increased from 2.86 K to 8.42 K. The sudden increase of Tc in LaO0.5F0.5Bi(S0.9Se0.1)2 results from the structural phase transition from tetragonal (P4/nmm) to monoclinic (P21/m). Structural phase transition pressure Pc of LaO0.5F0.5Bi(S0.9Se0.1)2 is higher than that of LaO0.5F0.5BiS2. The increase of Pc is ascribed to the suppression of the displacement parameter of the in-plane chalcogen site induced by chemical pressure of Se-substitution.