| Daryl Chapin (1906-1995), Calvin Fuller (1902-1994) and Gerald Pearson (1905-1987) Bell Labs 
Back in the 1950's Chapin, Fuller and Pearson were not planning to invent a solar cell, they were simply trying to solve problems
within the Bell telephone system. Traditional dry-cell batteries worked fine in mild climates but degraded too rapidly in the tropics
and ceased to work when needed. So the company asked its famous research arm-Bell Laboratories-to explore alternative sources of
freestanding power. Chapin got the assignment. Being a solar energy enthusiast, he suggested that the investigation include solar
cells.
Chapin began work in February 1952, but his initial research with selenium was unproductive. In March 1953, Pearson was pioneering semiconductor research with Fuller. They took silicon solid-state devices from the experimental stage to commercialization. Fuller, a chemist, had discovered how to control the introduction of the impurities necessary to transform silicon from a poor to a superior conductor of electricity. Fuller provided Pearson with a piece of silicon containing a small concentration of gallium. Pearson dipped the gallium-rich silicon into a hot lithium bath. The spot where the lithium penetrated created an area of poorly bound electrons and became negatively charged. Pearson conducted various tests on the rectifier. He shone light from a lamp onto the lithium-gallium silicon. An ammeter connected to the silicon recorded a significant electrical flow. Pearson had made a solar cell superior to any other available at the time. Pearson advised Chapin to switch to silicon. Chapin's tests on this new material proved Pearson right. Exposing Pearson's silicon solar cell to strong sunlight, Chapin found that it performed five times more efficiently than selenium. How's that for teamwork? |
