work From 1927 to 1928 Brattain worked for the National Bureau of Standards in Washington, D.C., where he helped to develop piezoelectric frequency standards. In August 1929 he joined Joseph A. Becker at Bell Telephone Laboratories as a research physicist. The two men worked on the heat-induced flow of charge carriers in copper oxide rectifiers. Brattain was able to attend a lecture by Arnold Sommerfeld. Some of their subsequent experiments on thermionic emission provided experimental validation for the Sommerfeld theory. They also did work on the surface state and work function of tungsten and the adsorption of thorium atoms. Through his studies of rectification and photo-effects on the semiconductor surfaces of cuprous oxide and silicon, Brattain discovered the photo-effect at the free surface of a semiconductor. This work was considered by the Nobel prize committee to be one of his chief contributions to solid state physics. At the time, the telephone industry was heavily dependent on the use of vacuum tubes to control electron flow and amplify current. Vacuum tubes were neither reliable nor efficient, and Bell Laboratories wanted to develop an alternative technology. As early as the 1930s Brattain worked with William B. Shockley on the idea of a semiconductor amplifier that used copper oxide, an early and unsuccessful attempt at creating a field effect transistor. Other researchers at Bell and elsewhere were also experimenting with semiconductors, using materials such as germanium and silicon, but the pre-war research effort was somewhat haphazard and lacked strong theoretical grounding. During World War II, both Brattain and Shockley were separately involved in research on magnetic detection of submarines with the National Defense Research Committee at Columbia University. Brattain's group developed magnetometers sensitive enough to detect anomalies in the earth's magnetic field caused by submarines. As a result of this work, in 1944, Brattain patented a design for a magnetometer head. In 1945, Bell Labs reorganized and created a group specifically to do fundamental research in solid state physics, relating to communications technologies. Creation of the sub-department was authorized by the vice-president for research, Mervin Kelly. An interdisciplinary group, it was co-led by Shockley and Stanley O. Morgan. The new group was soon joined by John Bardeen. Bardeen was a close friend of Brattain's brother Robert, who had introduced John and Walter in the 1930s. They often played bridge and golf together. Bardeen was a quantum physicist, Brattain a gifted experimenter in materials