Source: /cirosantilli/point-contact-transistor

= Point-contact transistor
{title2=BJT}
{title2=1947}
{wiki}

The first working one in 1947 by <John Bardeen> and <walter Brattain> in <Bell Labs Murray Hill>.

People had already <patented> a lot of stuff before without being able to make them work. Nonsense.

As the name suggests, this is not very sturdy, and was quickly replaced by <bipolar junction transistor>.