Dispersive concentrating systems based on transmission phase holograms for solar applications.

The efficiency of photovoltaic generators based on different semiconductor materials with optimized band gaps can achieve considerably higher values than those contained with single-junction solar cells. A new type of concentrating system is presented which allows high concentration and simultaneous splitting of the spectral region. This dispersive and concentrating (DISCO) system is based on volume phase transmission holograms which exhibit minimum absorption, high diffraction efficiency, and adjustable dispersion. The spectral imaging properties of volume phase transmission holograms can be optimized with respect to the requirements for solar applications.