By Kevin Bullis on January 30, 2015
Researchers have found a way to augment ordinary silicon solar cells with a material called a perovskite.
Putting a new kind of photovoltaic material on top of a conventional solar cell can boost overall power output by half. Researchers at Stanford University added a type of material known as a perovskite to a silicon solar cell, validating an idea for cheaply increasing the efficiency of solar power that was first proposed several years ago.
Perovskites are materials with a particular crystalline structure. The perovskite used by the Stanford team contains relatively abundant and cheap materials including ammonia, iodine, and lead.
perovskites also convert certain parts of the solar spectrum into electricity more efficiently than silicon, and vice versa, so the biggest efficiency gain may come from using perovskites to augment, rather than replace, the silicon in most solar cells
One of the main challenges with pairing perovskite cells with silicon ones has been rendering the former transparent, so that light they don’t absorb can pass through to the silicon cells beneath. The perovskite solar cells made previously used an opaque material on the back to collect electrical current. The Stanford researchers developed a manufacturing method that involves producing a transparent electrode made of silicon nanowires.
The researchers believe that perovskite-silicon cells will convert over 30 percent of the energy in sunlight into electricity. Such a boost would cut the number of solar panels for some installations almost in half, greatly lowering installation costs.