Entropy production in photovoltaic-thermoelectric nanodevices from the non-equilibrium Green’s function formalism

Fabienne Michelini (1) , Adeline Crépieux (2, 3) , Katawoura Beltako (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 CPT - Centre de Physique Théorique - UMR 7332
3 CPT - E6 Nanophysique

We discuss some thermodynamic aspects of energy conversion in electronic nanosystems able to convert light energy into electrical or/and thermal energy using the non-equilibrium Green's function formalism. In a first part, we derive the photon energy and particle currents inside a nanosystem interacting with light and in contact with two electron reservoirs at different temperatures. Energy conservation is verified, and radiation laws are discussed from electron non-equilibrium Green's functions. We further use the photon currents to formulate the rate of entropy production for steady-state nanosystems, and we recast this rate in terms of efficiency for specific photovoltaic-thermoelectric nanodevices. In a second part, a quantum dot based nanojunction is closely examined using a two-level model. We show analytically that the rate of entropy production is always positive, but we find numerically that it can reach negative values when the derived particule and energy currents are empirically modified as it is usually done for modeling realistic photovoltaic systems.

Mots clés: quantum dots; quantum thermodynamics; radiation laws; photovoltaics; non-equilibrium green's functions

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Physique Quantique [quant-ph]

Fabienne Michelini, Adeline Crépieux, Katawoura Beltako. Entropy production in photovoltaic-thermoelectric nanodevices from the non-equilibrium Green’s function formalism. Journal of Physics: Condensed Matter, 2017, 29 (17), pp.175301 ⟨10.1088/1361-648X/aa62e4⟩. ⟨hal-01789882⟩