2012/09/04 by David M.-T. Kuo, Yia‐Chung Chang, Kuo, David M. -T. +1
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.1209.0506
openalex publication_date 2012/09/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The thermoelectric properties of a semiconduct quantum dot chain (SQDC) connected to metallic electrodes are theoretically investigated in the Coulomb blockade regime. An extended Hubbard model is employed to simulate the SQDC system consisted of \colorblueN=2,3,4, and 5 quantum dots (QDs). The charge and heat currents are calculated in the framework of Keldysh Green's function technique. We obtained a closed-form Landauer expression for the transmission coefficient of the SQDC system with arbitrary number of QDs by using the method beyond mean-field theory. The electrical conductance (Ge), Seebeck coefficient (S), thermal conductance, and figure of merit (ZT) are numerically calculated and analyzed in the linear response regime. When thermal conductance is dominated by phonon carriers, the optimization of ZT is determined by the power factor (pF=S2Ge). We find that the optimization of ZT value favors the following conditions:(1) QDs with low energy level fluctuations, (2) QD energy levels lie above the Fermi level of electrodes, (3) Γ< tc ≪ U0, where tc, U0, and Γ are electron interdot hopping strength, on-site electron Coulomb interaction, and tunneling rate, respectively, and (4) ΓL=ΓR with ΓL+ΓR kept constant, where ΓL (ΓR) is the left (right) tunneling rate. It is predicted that high ZT values can be achieved by tailoring above conditions.