h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Diodes - A2565533
Author: Wooootton - U185009

This is the third article based on an essay for University coursework.

Have you read A762662 (Light-emitting Diodes)?

I'm a complete layman on subjects like this, so can't comment on any subject overlap... that said, the two things I reckon worth pointing out at this stage are:

1) There can only be one entry in the Edited Guide on any given subject - so an entry on Diodes would have to not overlap with the above one.
2) It looks on the surface like a good technical article (although I have factual basis for judging that!) but it's speaking to someone who already knows what you're talking about, rather than to someone that doesn't. I recommend a look at the Writing-Guidelines and also at A762662 to get an idea of the kind of thing accepted by the Edited Guide.



Cheers,
Number Six

It certainly seems to be diving in at the deep end, and I'd echo the above sentiments that it probably requires a lot of knowledge to understand (even to the point where someone who understood the physics would likely already know the application). It does seem to be part of a larger whole, or require prior knowledge of the construction of a semiconductor diode. For example, the first mention of a depletion region is at the end of the first section - anyone who already understood what a depletion region *was* from elsewhere would probably have some idea how a diode works already.


For the guide, I'm not sure it's worth going much beyond the level of the standard simplified description of semiconductor diodes:-

N-type semiconductor, excess of electrons
P type material, excess of holes
Explanation of recombination
Either P or N-type alone can conduct.
Combined together to make a diode, depletion region forms near junction where recombination results in lack of any carriers.
If reverse-biased, electrons and holes sucked further away from junction, depletion region increased in size - nothing available to carry current.
If slightly forward-biased, depletion region shrinks. If sufficiently biased, depletion region ceases to be a barrier, and useful current can flow right through device, but recombination still happens and consumes some voltage from the current flow.
etc.

Anything more detailed is only really useful for people who want to make or fundamentally understand them - it's quite sufficient for people who use them, or are just interested in a first-level description of how they work.

I'd also suggest starting off by saying what diodes are, and what they are used for, and maybe having a little on valves, then get to the semiconductor stuff.

Number Six, I think that an article purely on diodes as such wouldn't clash with the LED article - the coverage on rectification there was rather terse, and could be usefullly expanded in a new article, though it may be best to reduce or omit the LED section of this article and point to a762662 instead.

I have an entry on thermionic valves (A2521559) which is at an early stage, and would hope that this entry does not venture too far into that area. In fact, if it is suitable, I would hope that the introduction to A2521559 could link to this piece.

May I point out that
a) not all semiconductor diodes are of the junction type, nor made by diffusion, and
b) the point contact diode was a commercial success before the thermionic diode was used as a 'detector'

It may be more useful, at the level of the guide, to mention the various types of diode (point contact and junction) and the various materials in use (even today, these include copper oxide, selenium, germanium, silicon and gallium arsenide types), and even some history, rather than plunge headlong into donor/acceptor doping, fermi levels et cetera.

Nice idea for an Entry, but the current version looks (to me) more like a rough draft. I think it could use some polishing. I also agree with the comments above.

Bye,

HELL

The author seems to have left the building - back to entry or flea market for this one do we think?

Personally, I think this entry approaches the issue of diodes in far too technical a manner. If there is to be an entry on diodes, I would prefer to see it written from scratch in a simple style, rather than merely polishing this one up. So I would prefer to see this sent back to entry. I'm not a scout, so this is only advice, not a vote.

I'm minded to agree with you about that Gnomon. I consider myself to have a reasonable grounding in sciences, albeit not electronics, and I had real trouble following this.

Seconded for a move back to entry.

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