Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 3: Transport: Quantum Dots, Quantum Wires, Point Contacts
TT 3.13: Vortrag
Montag, 20. März 2017, 12:45–13:00, HSZ 201
Role of incoherent scattering on energy filtering in nanostructured thermoelectric generators — •Aniket Singha and Bhaskaran Muralidharan — Department of Electrical Engineering, IIT Bombay, Powai, Mumbai-400076, India
We employ the incoherent non-equilibrium Green’s function formalism to investigate in detail the physics of energy filtering and how it leads to an enhancement in power generation across nanostructured thermoelectrics featuring a single planar energy barrier. In particular, we reinforce that the enhancement in the generated power via energy filtering is a characteristic of incoherent scattering and is absent in ballistic devices. By assuming an energy dependent relaxation time, τ(E)=kEr, we show that there exists a minimum value rmin for which the thermoelectric power generation is enhanced and thereby leading to a degradation in power generation for r<rmin. For bulk generators, we delve into the details of intermode scattering and show that such scattering processes between electrons in higher energy modes and lower energy modes have a finite contribution to the enhancement in the generated power. We also discuss realistic aspects such as finite width of energy barriers and imperfect energy filtering due to partial reflections. In particular, we show that such imperfect filtering and partial transmission of electrons near the top of the barrier affects the enhancement in the generated power drastically in the high efficiency regime of operation.
[1] A. Singha and B. Muralidharan, ArXiv: 1609.07894, (2016)