Short answers, pulled from the story.
Michael Faraday made the observation in 1833 that the resistance of silver sulfide decreased when it was heated. This finding defied the physics of his time and established the core property of semiconductors.
The cat's-whisker detector became the first working semiconductor device in 1904. This crude diode used a piece of galena and a thin wire to detect radio waves in early receivers.
John Bardeen, Walter Brattain, and William Shockley invented the point-contact transistor in 1947 at Bell Labs. This device could amplify signals and replaced bulky vacuum tubes to enable circuit miniaturization.
Doping changes electrical properties by adding a tiny amount of impurity such as one atom of arsenic for every ten million atoms of silicon. This process creates n-type semiconductors with excess electrons and p-type semiconductors with excess holes.
Silicon is the dominant material because it is abundant in the Earth's crust and forms a stable oxide layer called silicon dioxide. This oxide layer is crucial for creating insulating layers in integrated circuits.
World War II drove the development of semiconductor technology through the urgent need for better radar and communication systems. Vacuum tubes could not operate effectively at high frequencies, leading to the use of point-contact crystal detectors made from materials like lead sulfide and lead selenide.