 During his time there, he continued to work with germanium and silicon.When William Shockley's group at Bell Labs invented the transistor in 1947 Teal realized that substantial improvements in the device would result if it was fabricated using a single crystal, rather than the polycrystalline material then being used, and created the grown junction single crystal technique.In 1952 Dallas-based Texas Instruments had purchased a license to produce germanium transistors from Western Electric, the manufacturing arm of AT&T and placed an ad in the New York Times for a director of research.