Reversible electron-hole separation in a hot carrier solar cell

摘要: Hot-carrier solar cells are envisioned to utilize energy filtering extract power from photogenerated electron-hole pairs before they thermalize with the lattice, and thus potentially offer higher conversion efficiency compared conventional, single absorber cells. The of hot-carrier can be expected strongly depend on details process, a relationship which date has not been satisfactorily explored. Here, we establish conditions under separation in occur reversibly, that is, at maximum efficiency. We focus our analysis internal operation cell itself, this work do consider photon-mediated coupling sun. After deriving an expression for voltage valid both reversible irreversible electrical operation, identify separate contributions thermoelectric effect photovoltaic effect. find that, specific conditions, exceed Carnot limit set by intra-device temperature gradient alone, due additional contribution quasi-Fermi level splitting absorber. also open-circuit is limited band gap absorber, voltage. Additionally, operated reverse as thermally driven solid-state light emitter. Our results help explore fundamental limitations cells, provide first step towards providing experimentalists guide optimal configuration devices.