Comments by "Lawrence D’Oliveiro" (@lawrencedoliveiro9104) on "Transistors - The Invention That Changed The World" video.

  1. Actually, the first transistors were germanium, not silicon. And other materials have been tried as well, e.g. gallium arsenide. Also note that the “doping” process uses such tiny traces of the additional elements to make such a big change to its electrical properties, the substrate would still for many purposes be considered “chemically pure”.
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  2. 4:43 A key thing happening here, as with the triode vacuum tube, is amplification : a small-amplitude signal can be used to control the amplitude of a much larger voltage or current, producing a stronger version of the same signal (barring well-known limitations like noise and distortion).
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  3. Quantum tunnelling is itself integral to how transistors (and vacuum tubes) work in the first place.
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  4. Fun question to contemplate: the transistor was an American invention; so why did the Japanese take it and run with it, to produce well-known transistorized appliances (transistor radios and the like) from the 1960s onwards? In the US there was already an established consumer-electronics industry, based on vacuum tubes. The reason was precisely those vacuum tubes. The US industry had a great deal invested in them over many prior decades, which it was reluctant to give up. The Japanese were starting from nothing, so they were free to adopt the new technology. This is an example of a “disruptive technology”, where the existing players will not adopt the new idea because they see it as a threat, either to themselves or their existing customers. And so it is left to new players to come in and take over the market.
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  5. 3:55 No it doesn’t. The substance is still neutral, because the phosphorus nucleus still has that extra proton to counter the charge of the extra electron. The terms “n-type” and “p-type” just say that the “majority charge carriers” (quantum entities that flow to carry the current) are negatively-charged electrons in the one case, and positively-charged “holes” (actually, the absence of an electron) in the other case.
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