Quantum thermoelectric effects in nonequilibrium bipolar semiconductors

In this study, thermoelectric transport through a quantum structure embedded in a bipolar semiconductor is theoretically investigated using a quantum point contact (QPC) as an example. This study focuses on the conditions under which nonequilibrium charge carriers exist in the semiconductor. Two key factors are analyzed in detail: the anisotropy of the charge carrier distribution function near the quantum system and the emergence of quasi-Fermi levels in its immediate vicinity. The analysis was performed within the single-electron approximation using the Landauer–Büttiker formalism. It was found that the conductance of the QPC is affected solely by the anisotropy of the charge carrier distribution function. In contrast, both mechanisms of the nonequilibrium significantly influence the Seebeck coefficient of the quantum system with bipolar semiconductor leads.