- Multi-phase thermoelectric materials are widely investigated due to their high potential for thermoelectric efficiency enhancement as a result of lattice thermal conductivity reduction by phonon scattering from the involved interfaces. Yet, the electronic mutual influence of the involved phases on the thermoelectric efficiency has to date usually been neglected in designing novel multi-phase thermoelectric materials. In the current research, the influence of distribution and morphology alignment on the electronic thermoelectric properties of three-phase composite materials was analyzed. Such an analysis, based on defining interaction volumes of the relevant thermoelectric properties, for any distribution and relative amount of any three phases with known individual properties, can be utilized for thermoelectric efficiency enhancement by intentional alignment of the phases along the preferred thermoelectric direction. For the p-type Gex(SnyPb1−y)1−xTe thermoelectric alloys, following a phase separation reaction it was found that serially relative alignment between the involved phases is optimal from the thermoelectric point of view.