Three-Dimensional Point-Focus Spectral Splitting Solar Concentrator System

Spectral splitting solar systems are emerging as alternative solutions to multi-junction solar cells for cost effective high efficiency photovoltaic applications. We have recently proposed a low cost single element splitting system based on a prismatic structure able to contemporary split the solar light into its spectral component and concentrate them. Here a new design of the spectral splitter is proposed and the optimization study of the entire solar system (solar splitter and solar cells) is conducted. The considered spectral splitter/concentrator consists of a three-dimensional point-focus system made of a disposition of dispersive elements. The advantages of this new design are discussed in detail and results of the optical simulations are reported. The optical system is then combined with a set of three solar cells, each of them illuminated with a different spectrum band. Simulations with Sentaurus TCAD are carried out with the aim of optimizing the electrical and geometrical properties of the devices. We obtained an overall efficiency of 28 %, which represents a good starting point for spectral splitting solar systems to compete with multi-junction solar cells technology.