Lattice Thermal Conductivity of Disordered Alloys of Ternary Compound Semiconductors Cu₂(Sn, Ge)(Se, S)₃(Ag, Pb, Sb)Te₂, and (Ag, Sn, Sb)Te₂

Lattice thermal conductivities of Cu 2 SnSe 3 -Cu 2 SnS 3 , Cu 2 SnSe 3 -Cu 2 GeSe 3 , Cu 2 Sn 0.8 Ge 0.2 Se 3 -Cu 2 Sn 0.8 Ge 0.2 Se 3 and Cu 2 Sn 0.6 Ge 0.4 Se 3 -Cu 2 Sn 0.6 Ge 0.4 Se 3 alloy systems have been determined as functions of the alloy compositions. Experimental results are compared with the Klemens-Drabble theory. Agreement between the theory and the experiment is good for Cu 2 SnSe 3 -Cu 2 SnS 3 system, while the experimental values are appreciably below the theoretical curve for Cu 2 SnSe 3 -Cu 2 GeSe 3 system. The discrepancy may be due to a contribution of strain to phonon scattering. In the case that both anionic sublattice and catonic sublattice are disordered as in alloy systems of Cu 2 Sn 0.8 Ge 0.2 Se 3 -Cu 2 Sn 0.8 · Ge 0.2 S 3 or Cu 2 Sn 0.6 Ge 0.4 Se 3 -Cu 2 Sn 0.6 Ge 0.4 S 3 , it was found that the resultant scattering parameter is given by the sum of the individual effects. Lattice thermal conductivities of AgSbTe 2 -PbTe and -SnTe systems have been re-investigated and compared with the theory. Qualitative agreement between the experimental data and the theoretical curves is obtained except for the PbTe-rich alloys in AgSbTe 2 -PbTe system.