The first practical high efficiency (6%) cell was made in Bell Laboratories in 1954. It was the first PN junction silicon solar cell, the technology that still

The first practical high efficiency (6%) cell was made in Bell Laboratories in 1954. It was the first PN junction silicon solar cell, the technology that still powers 90% of solar cell modules on the market. http://www.aps.org/publications/apsnews/200904/physicshistory.cfm http://www.aps.org/publications/apsnews/200904/physicshistor...