Electromagnetic approach to ultrathin solar cell efficiencies

TL;DR

This paper introduces a rigorous electromagnetic method based on the fluctuation dissipation theorem to evaluate the efficiency of ultrathin solar cells, accounting for near field optical effects that traditional methods overlook.

Contribution

It presents a novel electromagnetic approach for calculating ultrathin solar cell efficiencies, addressing limitations of existing methods for near-field phenomena.

Findings

Near field optics significantly influence ultrathin solar cell performance

Efficiency calculations for GaAs cells with Au reflectors show notable effects at sub-wavelength thicknesses

The method enables accurate efficiency predictions for extremely thin photovoltaic devices

Abstract

Current methods for evaluating solar cell efficiencies cannot be applied to extremely thin cells where phenomena from the realm of near field optics prevail. We overcome this problem by offering a rigorous electromagnetic calculation of solar cell efficiencies based on the fluctuation dissipation theorem. Our approach is demonstrated by calculating the efficiency of a GaAs solar cell with an Au back reflector for thicknesses well below the typical wavelength of the solar flux. It is shown that near field optics affect the performance of low dimensional solar cells.