Science Daily October 3, 2022
Traditional solar thermophotovoltaics (STPVs) rely on an intermediate layer to tailor sunlight for better efficiencies. However, the thermodynamic efficiency limit of STPVs is still far lower than the Landsberg limit (93.3%), the ultimate efficiency limit for solar energy harvesting. Researchers at the University of Houston showed that the efficiency deficit is caused by the back emission of the intermediate layer towards the sun resulting from the reciprocity of the system. They proposed nonreciprocal solar thermophotovoltaics (NSTPV) that utilize an intermediate layer with nonreciprocal radiative properties. Such a nonreciprocal intermediate layer could substantially suppress its back emission to the sun and funnel more photon flux towards the cell. They showed that, with such improvement, the NSTPV system can reach the Landsberg limit, and practical NSTPV systems with single-junction photovoltaic cells can also experience a significant efficiency boost… read more. Open Access TECHNICAL ARTICLEÂ
The trade-off in spatial and angular concentration of rays due to the étendue conservation. Credit: Phys. Rev. Applied 18, 034083, 29 September 2022Â