Thermoelectric properties of finite two-dimensional quantum dot arrays with band-like electronic states

Abstract

The thermal power ( PF = S 2 G e ) depends on the Seebeck coefficient ( S ) and electron conductance ( G e ). The enhancement of G e will unavoidably suppress S because they are closely related. As a consequence, the optimization of PF is extremely difficult. Here, we theoretically investigated the thermoelectric properties of two-dimensional quantum dot (QD) arrays with carriers injected from electrodes. The Lorenz number of 2D QD arrays in the resonant tunneling procedure satisfies the Wiedemann-Franz law, which confirms the formation of minibands. When the miniband center is far away from the Fermi level of the electrodes, the electron transport is in the thermionic-assisted tunneling procedure (TATP). In this regime, G e in band-like situation and S in atom-like situation can happen simultaneously. We have demonstrated that the enhancement of G e with an increasing number of electronic states will not suppress S in the TATP. • The formation of minibands of 2D QD arrays is confirmed by the Wiedemann-Franz law in the resonant tunneling procedure. • The electron transport between the electrodes is in the thermionic-assisted tunneling procedure (TATP), as the miniband center is far away from the Fermi level of the electrodes. • In TATP, G e in band-like situation and S in atom-like situation can happen simultaneously. • The enhancement of G e with an increasing number of electronic states will not suppress S in the TATP.