What was Brattain's main theory or idea?
My main idea was that the real action in semiconductors happens at the surfaces—the dirt and the imperfections. Most theorists back then thought the bulk material was all that mattered, but I knew from my experiments that surface states, those little traps for electrons, controlled how a metal-semiconductor contact behaved. John Bardeen and I worked out that these surface states could pin the Fermi level and mess up rectification. That insight led directly to the point-contact transistor: by putting two contacts close together on a germanium surface, we could use one to inject carriers and the other to amplify them. It's all about the surfaces, I tell you. You can't think your way to that; you have to build it and measure it. That's why I always said, 'You have to get your hands dirty to understand.'
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