Optimization of the Thermoelectric Figure of Merit in Crystalline C₆₀ with Intercalation Chemistry

Abstract

Crystalline C₆₀ is an appealing candidate material for thermoelectric (TE) applications due to its extremely low thermal conductivity and potentially high electrical conductivity with metal atom intercalation. We investigate the TE properties of crystalline C₆₀ intercalated with alkali and alkaline earth metals using both classical and quantum mechanical calculations. For the electronic structure, our results show that variation of intercalated metal atoms has a large impact on energy dispersions, which leads to broad tunability of the power factor. For the thermal transport, we show that dopants introduce strong phonon scattering into crystalline C₆₀, leading to considerably lower thermal conductivity. Taking both into account, our calculations suggest that appropriate choice of metal atom intercalation in crystalline C₆₀ could yield figures of merit near 1 at room temperature.