The conversation between human and AI assistant.
[|Human|] Based on the following passage describe the first solid-state device and its use.
[|AI|] The first solid-state device was the "cat's-whisker detector" first used in the 1900s in radio receivers. A whisker-like wire is placed lightly in contact with a solid crystal (such as a germanium crystal) to detect a radio signal by the contact junction effect.
[|Human|] 
Based on the following passage describe the first solid-state device and its use.