▎ 摘　　要

Thermoelectric devices convert heat energy to electric power. The dimensionless thermoelectric figure of merit, ZT, is used as a standard criterion for efficiency of thermoelectric conversion. This criterion requires a high Seebeck coefficient, a high electric conductivity, and a low thermal conductivity. In this regard, PbTe, BiTe, and their alloys consisting of relatively heavier elements have been found to show higher values of ZT. In this paper, we focus on the potential of graphene-based composites as thermoelectric materials. Graphene was considered to be a disadvantageous material because of its extremely high thermal conductance and relatively low Seebeck coefficient. However, it has been reported recently that a structural modulation is an effective way of raising the thermoelectric ability of graphene. We introduce the recent progress in the design of graphene-based materials for thermoelectric devices. In particular, we provide a focused investigation of our recent progress regarding the thermopower enhancement in nanoarchitectonics, superlattices, and composites consisting of graphene and hexagonal BN nanoribbons. It has been shown that low-dimensional modulations are effective ways of obtaining a high thermoelectric performance of graphene-based materials. (C) 2016 The Japan Society of Applied Physics