Making complete PV cells and arrays
Newsprint and copy paper
These photos show single PV cells deposited on newsprint (top) and on copy paper (bottom). The dark gray area is the anode; blue is the photoactive layer; and silver is the cathode coming from the other side. In the left sample, the text of the newspaper is still visible—undisturbed by the dry deposition of the PV materials. The right sample is folded, but it still functions.
A working PV cell, of course, requires more than just an anode. Deposition of the remaining components takes place in Bulovic’s lab. He and his team use evaporation, another dry process but with no chemical reactions involved. They take a material in solid form, heat it until it becomes a gas, and then allow it to condense on the surface of interest. Using that approach, they coat the PEDOT anode with several “photoactive” nanostructured thin films—the layers that absorb light and cause electrons to flow—and then finally the cathode (the negative electrode). The result is a complete PV cell. The photos on this page show single cells printed on newsprint and copy paper.