A four-terminal solid-state device developed in the early days of semiconductor research that injected electrons directly into a high-field space-charge region. By forcing carriers to travel rapidly through this depletion zone, designers hoped to achieve much higher switching frequencies than standard bipolar junction transistors of the era. It was ultimately superseded by improvements in conventional transistor manufacturing.
Heard on the job
The spacistor was an interesting dead end in the race to build high-frequency solid-state amplifiers.