Meanwhile , Gerald Pearson did important early work investigating the properties of silicon .
Teal 's group built the first grown - junction germanium transistors , which were announced by Shockley at a press conference on July 4 , 1951 .
Gerald Pearson did important early work investigating the properties of silicon .
Teal 's group built the first grown - junction germanium transistors , which were announced by Shockley at a press conference on July 4 , 1951 .