High-efficiency spectrum splitting for solar photovoltaics

• An efficient spectrum splitting scheme is found.
• The detailed balance limit efficiency of the scheme reaches 48.3%.
• An analytical approach to calculate realistically achievable efficiency is presented.
• According to the experimental based estimations 41.5% efficiency is achievable.

A linear solar-tracking spectrum-splitting scheme for solar photovoltaics is investigated. The investigation is made by means of a numerical optimization and an analytical approach to predict conversion efficiency based on available experimental data. For a simple spectrum splitting scheme, a high conversion efficiency limit of 43% without and 48% with solar concentration is predicted for two single junction solar cells. It is also shown that efficiencies of at least 37% and 41% are to be expected if state of the art cells are used. The investigation was performed using a Fourier Modal Method electromagnetic solver based on the scattering matrix formalism combined with a numerical optimizer utilizing the Evolution Strategy.