How the first transistor worked ?

Maybe we need to know How the first transistor worked !

Bill uses a replica of the point contact transistor built by Walter Brattain and John Bardeen at Bell Labs. On December 23, 1947 they used this device to amplify the output of a microphone and thus started the microelectronics revolution that changed the world. He describes in detail why a transistor works by highlighting the uniqueness of semiconductors in being able to transfer charge by positive and negative carriers.