Thermal conductivity of Bi2(SexTe1-x)3 alloy films grown by molecular beam epitaxy

We studied the thermal conductivity of Bi2Se3, Bi2Te3, and their alloy Bi-2(SexTe1-x)(3) at room temperature using time-domain thermoreflectance measurements. The Bi-2(SexTe1-x)(3) films with various concentrations of Se and Te prepared by molecular beam epitaxy on GaAs substrates were investigated to study the dependence of thermal conductivity on film composition. We observed that the Bi-2(SexTe1-x)(3) ternary alloys can have much lower thermal conductivity values compared to those of Bi2Se3 and Bi2Te3. These results may provide useful information for developing and engineering low thermal conductivity materials for thermoelectric applications. (C) 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.