Matt Francis and his research colleagues at The University of California at Berkley have engineered a tobacco plant virus that has evolved to created electrical energy from solar radiation.
When injected with an engineered virus, tobacco plants are forced to create artificial chromophores.
The virus, when injected does naturally what would be nearly impossible to do by engineering the tobacco plant itself. They go into each cell within the plant (as viruses naturally do) and tinker with the cell to make it start the chromophore production. These chromophores then are harvested from the plants, extracted and sprayed onto a glass substrate panel for use. The spray would have to be re-applied every so often. While much less efficient than the standard 10-40% for standard silicon or CIS based solar cells (they may operate at 3-5%), they are also extremely inexpensive and easy to produce in large quantities. Actual production is many years down the road as the research is still in the concept stage.
The idea of spray-on photovoltaic material has obvious applications in sculptural form. Complex geometries could be transformed into electrical generating machines. There may be interesting qualities of the reflection of light off of these spray on chromophores.