New uses for amorphous silicon

Ever since 1975, when Walter Spear and Peter Le Comber of the University of Dundee in Scotland demonstrated that one could vary the conductivity of amorphous silicon over ten orders of magnitude by doping, there has been much excitement over the possibility of using this inexpensive material to make practical large‐area solar cells. At about the same time, David Carlson and Christopher Wronski were producing amorphous‐silicon solar cells with 5.5% efficiency at RCA.