Florian Proise

Micro solar concentrators: Design and fabrication for microcells arrays

In this work we look at a micro-concentrating system adapted to a new type of solar concentrator photovoltaic material, well known for flate-plate applications, Cu(In,Ga)Se2. Cu(In,Ga)Se2 solar cells are polycrystalline thin film devices that can be deposited by a variety of techniques. We proposed to use a microcell architecture [1], [2], with lateral dimensions varying from a few μm to hundreds of μm, to adapt the film cell to concentration conditions. A 5% absolute efficiency increase on Cu(In,Ga)Se2 microcells at 475 suns has been observed for a final efficiency of 21.3% [3]. We study micro-concentrating systems adapted to the low and middle concentration range ([4], [5]), where thin film concentrator cells will lead to substrate fabrication simplification and costs savings. Our study includes optical design, fabrication and experimental tests of prototypes.

InP-based nano solar cells

Light trapping enhancement is a major research field in photovoltaics. Scarce and expensive resources for semiconductor material drive the research on light management in thin absorber layer. This paper reviews some of the known techniques, from back reflector to nanophotonic technologies such as nanowires or plasmonic-enhanced photovoltaic devices. Light trapping enhancement can reach ~100 fold and experimental demonstrations of device exceeding the ray optics limits have been reported.

Structured InP-based nanoantenna for photovoltaics applications

Abstract. Nanoresonators are used in photovoltaic applications to reduce the absorber volume by confining the electromagnetic fields. We employed a two-dimensional Maxwell equation solver to investigate the optical performance of a fully structured InP-based nanoresonator, allowing high optical absorption and being electrically compatible. We demonstrated a 60% broadband optical efficiency with a good angle tolerance: more than 40% optical efficiency for an incidence angle between 60 deg and 60 deg. We also addressed the fabrication process in identifying the main barriers and in proposing technological solutions.