Optimization of the thermoelectric properties of Ba8Ga16Ge30

Polycrystalline Ba₈Ga₁₆Ge₃₀ clathrates with a systematic variation in the Ga:Ge stoichiometry were prepared to investigate the thermoelectric properties as a function of carrier concentration. Their corresponding transport properties were evaluated to identify the optimal carrier concentration for high temperature thermoelectric performance. These polycrystalline specimens demonstrate thermoelectric properties comparable to those obtained in single-crystal Ba₈Ga₁₆Ge₃₀, confirming that polycrystalline clathrates can be optimized for high temperature thermoelectric applications.