Transistor

Transistors were discovered as more reliable and efficient alternatives to radio tubes, consisting of semiconductors that could serve multiple functions such as amplifying and rectifying electric current. They marked a significant technological advance, replacing radio tubes due to their small size, low energy consumption, and ruggedness.
 William Bradford Shockley, Walter Houser Brattain, John Bardeen United States 1948 Transistor

Transistors were discovered as more reliable and efficient alternatives to radio tubes, consisting of semiconductors that could serve multiple functions such as amplifying and rectifying electric current. They marked a significant technological advance, replacing radio tubes due to their small size, low energy consumption, and ruggedness.