spray on solar cells
Posted: Sat Jun 30, 2012 7:18 pm
Sitting to my right is a box of 6" square monocrystaline solar cells, for a project I'm working on. Ordered straight from China. Some processes describe this type as being "printed" on foil. The cell itself is incredibly thin, comparable to a thin spray of paint on a thin aluminum sheet. The suckers can probably crank out four amps or more at around half a volt. For this small order I paid around $76 for around 40 watts, and in quantity you can get down to around a buck a watt.
I'm not up with the latest methods for these particular cells, but I know some methods these days involve silane gas, and the term "spraying" is not that far off. The modern ones are a huge departure from early cells, which were made by slicing whole 3" or 4" solid zone-refined silicon cylinders into wafers. The total silicon in each of these is a tiny fraction of an old 4". Plus they fit better in a panel.