▎ 摘　　要

The thermal, electrical and thermoelectric properties are investigated in graphene-nanoribbon-stacked heterojunctions by applying the density functional theory combined with the nonequilibrium Green's function technique. Our calculations show that layer-layer interaction (LLI) can form a large current and electron thermal conductance, and the current and electron thermal conductance are highly sensitive to the geometry details of the layer-stacked structure. Especially, negative differential resistance (NDR) behaviors can be found in the stacked nanoribbon structures. More importantly, different from two-dimensional materials that possess massless Dirac fermions (Zhou et al. (2016), the LLI in stacked quasi-monolayer nanoribbon structures can lead not only to low ratio K-e/(GT) (which is much lower than the constant L-0 = 2.44x10(-8) W Omega K-2) but also to the high seebeck coefficient near mu = 0, which leads to very high figure-of-merit value: the figure-of-merit will be over 6.5 in 4-3.6-2.5-ZGNR and over 3.5 in 4-3.0-2.1-ZGNR at room temperature. The results shed light on its potential application in a multifunction device by applying the LLI, containing NDR effect and thermoelectric technologies.