Thermoelectric property regulation of Au₂@C₆₀/AGNR hybrid junctions based on interfacial structural entropy...

High-entropy thermoelectrics effectively reduce phonon thermal conductance through disordered phonon scattering, which has become a topic of interest among researchers. In this work, the thermoelectric properties of Au₂@C₆₀/AGNR hybrid nanodevices under three different coupling configurations (AA, AB and SP) were systematically investigated by employing first-principles calculations combined with the non-equilibrium Green's function (NEGF). Local structural disorder and the corresponding structural entropy were obviously enhanced, which mostly originated from charge redistribution and vibrational mode distributions between Au₂@C₆₀ and the graphene substrate as well as the neighboring C atoms around Au₂. Notably, the structural entropy response scales with the stacking configuration and strictly follows the order ΔS_AA > ΔS_AB > ΔS_SP, which means that the AA-stacked junction possesses maximized phonon scattering behavior and minimized phonon thermal conductance. Meanwhile, local electronic restructuring and band modulation of the AA-stacked configuration induced by high-entropy regulation lead to a large charge carrier density and a high Seebeck coefficient. As a result, the AA-stacked junction achieved an optimal ZT of 0.26, which was an order of magnitude higher than those of the AB and SP architectures. This work provides a solid theoretical foundation for designing high-entropy-regulated thermoelectric applications in low-dimensional carbon hybrids.