Nonideal absorbers in hot-carrier and hot-absorber solar cells: Losses and heat recycling
Phys. Rev. Applied 26, 034049 – Published 22 September, 2026
DOI: https://doi.org/10.1103/7gjt-qhd4
Abstract
The hot carrier solar cell exhibits a photovoltaic conversion efficiency limit of 85.4%. Among the idealizations necessary to achieve this efficiency, it has traditionally been considered essential that the electrons absorbing sunlight do not end up transferring the captured energy to the crystal lattice. In this work, we argue that such a requirement is not necessary if the absorber is thermally insulated. In our analysis, we also consider the possibility of Ohmic losses in the absorber due to finite electrical conductivity. We also demonstrate that such losses, delivered as heat, can be partially recycled into electrical work with an efficiency that is given by the Carnot factor. The high efficiencies reported here are thermodynamic limits obtained with ideal energy-selective contacts and negligible parasitic contact conductance, not projections of practical device efficiency. Our work includes a sensitivity analysis for finite contact-mediated heat leakage, and the results are presented as design targets.
