As stated in an official history of Bell Labs, "Timely invention of zone refining by W.G.Pfann ... was a major contribution that helped bring the impurities in germanium and silicon under control.
Showing unusual facility with materials, in 1935, when he was only eighteen years of age, he started with the Chemical Research Department of Bell Labs.
[2]: 198 Pfann was involved in William Shockley's efforts with Bell Labs to use semiconductors to make devices to replace vacuum tubes.
[4][2]: 180 Pfann also invented a method of bonding fine gold wires to germanium that made the device functional.
[2]: 189 "The quiet, unassuming man grew steadily in everyone's esteem as he made one valuable contribution after another to the semiconductor research effort.
[2]: 199 In 1952, Pfann published the revelatory article "Principles of Zone-Melting" in the Transactions of the American Institute of Mining, Metallurgical, and Petroleum Engineers.
On his passing some coworkers wrote: His energy, his high standards of honesty in experimentation and his unprejudiced approach to the new, the untried, and even the heretical, helped define the word scientist for a large number of his acquaintances.