Photovoltaics is a key technology within alternative energies. Solar cells enable generation of electricity for a wide range of applications: large scale utilities, commercial and residential roof top installations and various other on-grid and off-grid application. Improving the cell efficiency and reducing the manufacturing cost of solar cells will even increase this broad range of applications.

UV Imprinting provides an easy and cost efficient manufacturing process for micro-optical elements. UV imprinting enables the replication of any kind of optical features: spherical and a-spherical lenses, diffractive optical elements and functional optical films.

Microlenses focus and concentrate the incident light directly on the photovoltaic cell. With microlenses it is possible to use multiple micro-PV cells instead of large CPV cells. The form factor of CPV modules using micro-optics is significantly smaller enabling ultra-thin and even flexible CPV modules. Compared to large concentrating optics the microlenses can be manufactured on a flexible film, which allows using micro-optics also for non-flat surfaces.

An interesting alternative to direct concentration on the PV cell is coupling of the incident light into a wave guide. At the end of the waveguide a secondary concentrating micro-optic can be used to optimize the light angle to the PV cell.


Microlenses are being used for
a) direct concentration of the incident light on PV cells and
b) coupling the incident light into
a waveguide. Courtesy of UC San Diego

Cross section showing the micro lens array and the waveguide. Courtesy of UC San Diego