First-principle calculation of solar cell efficiency under incoherent illumination

TL;DR

This paper presents a first-principles analytical method to calculate the efficiency of solar cells under incoherent sunlight by convolving the coherent efficiency with a light incoherence function, simplifying previous computational approaches.

Contribution

The authors derive an analytical convolution-based method from Maxwell's equations to compute incoherent solar cell efficiency, avoiding extensive numerical simulations.

Findings

The method accurately reproduces incoherent efficiency from coherent calculations.

Good agreement with previous numerical methods is demonstrated.

The approach simplifies the analysis of solar cell performance under real sunlight conditions.

Abstract

Because of the temporal incoherence of sunlight, solar cells efficiency should depend on the degree of coherence of the incident light. However, numerical computation methods, which are used to optimize these devices, fundamentally consider fully coherent light. Hereafter, we show that the incoherent efficiency of solar cells can be easily analytically calculated. The incoherent efficiency is simply derived from the coherent one thanks to a convolution product with a function characterizing the incoherent light. Our approach is neither heuristic nor empiric but is deduced from first-principle, i.e. Maxwell's equations. Usually, in order to reproduce the incoherent behavior, statistical methods requiring a high number of numerical simulations are used. With our method, such approaches are not required. Our results are compared with those from previous works and good agreement is found.