Talk:P–n junction

Depletion zones

The explanation of PN junction operation is really the explanation of Depletion zones. --Wjbeaty 07:14, Apr 3, 2005 (UTC)

Non-rectifying Junctions

Schottky diodes do not have P-N junctions. They have metal-semiconductor junctions (See Schottky_barrier) Tonsofpcs 18:52, 13 May 2005 (UTC)

Corrected. - mako 18:56, 13 May 2005 (UTC)

Any chance of show the "barrier potential" in a diagram, i have one but it is not good quality, and more of a ditty on it —Preceding unsigned comment added by Acwcook (talk • contribs) 17:09, 11 July 2008 (UTC)

Merger proposal

The proposed merger of Reverse-biased into p-n junction#Reverse-bias sounds like a good idea. It really is a feature/effect of the junction, not much to say on its own, and need to discuss the junction to understand it anyway. DMacks 21:51, 18 September 2007 (UTC)

In the discussion of the functioning of a P-N junction as a rectifier, clearly consideration of both forward-bias and reverse-bias is essential. (Arnold Whapham, Nov 19, 2007) —Preceding unsigned comment added by 24.6.170.15 (talk) 02:51, 20 November 2007 (UTC)

If forward biased hasnt got its own article, i see no reason why reverse biased should, so i support either merging the article, or giving forward biased its own article also for consistency 193.60.83.241 (talk) 16:24, 13 May 2008 (UTC)

Error and question

Figure B is mislabeled. Should be "charge density", $\rho$, instead of "charge", Q. Greengadgetz (talk) 15:38, 13 March 2008 (UTC)

Where should I put information on how to calculate carrier concentrations and such? Greengadgetz (talk) 15:38, 13 March 2008 (UTC)

Mathematical Analysis

Is there a reason that no mathematical analysis of the operation of a PN junction has been included in this article? 69.134.60.173 (talk) 03:41, 17 March 2008 (UTC)

Information

I suggest add information about heterojunctions and multijunctions.--Mac (talk) 11:57, 15 September 2008 (UTC)

Format of "See also" section

I think formatting the "See also" section, as edited by 69.225.251.134, looks bad. Since 69.225.251.134 has been making the same change all over the place, I will be opening a discussion on this at Wikipedia talk:Manual of Style. --Jc3s5h (talk) 15:08, 18 July 2009 (UTC)

It's certainly bad, and the user has also been making other dubious changes (mostly by subtly changing words, usually with IMHO a detrimental effect), so I have warned them about it. I have to say that, regrettably, virtual every article they edited, as seen on their list of contributions, looks to have been edited dubiously (I think I have fixed most, but I would be grateful if others had a look). --LjL (talk) 16:30, 18 July 2009 (UTC)

"Holes" theory it's confusing

Holes are used just for dumb explanation in basic electronics books, they have no physical existence. Please update the theory. It's silly to use expresions like "the holes are pushed". How can one push non-existent things like holes ? :-) —Preceding unsigned comment added by 79.114.18.65 (talk) 18:17, 1 August 2009 (UTC)

I'm a grad student in condensed matter physics and I can assure you you're 100% wrong. A hole is a physically real quantum excitation of a semiconductor. It has a definite, well-defined mass (which is NOT negative, and NOT the same as the mass of a free electron), and it can undergo collisions. In fact, the quantum excitation called an "electron" is not really the same as a free electron at all, because it also has a different mass from a free electron. It is another kind of quantum excitation that isn't the same as a single free particle, but nevertheless it's perfectly "real" in that it accurately describes the low-energy quantum states of the semiconductor system. So if you want to say "holes aren't real", then you have to say that these kinds of "electrons" in a semiconductor aren't real either. If holes aren't real, then what the heck is a exciton made of?? —Keenan Pepper 15:20, 2 August 2009 (UTC)

You are welcome ! My point here is to show that the "semiconductor" device was put together by experiment. People really started to play with crystals and they got something ... that was so strange even for a "scientist". Someone came with a theory full of holes and electrons. Then comes the quantum stuff. I like the old man saying: 'It is safe to say that nobody understands quantum mechanics.'( Richard Feynman ). So, the theory is just after the real stuff. Unfortunately, the experiments are still confidential. We may never know how really the transistor was "invented" or works. We may know that what we use and know as viable theory today is a real junk. —Preceding unsigned comment added by 79.114.86.222 (talk) 18:32, 2 August 2009 (UTC)

Okay... if you want to talk about experiment rather than theory, then how do you explain the Hall effect in a p-type semiconductor if holes aren't real?

I really take offense at your assertion that holes are only for "dumb explanation in basic electronics books". Current articles in peer-reviewed physics journals discuss holes.

Also, I don't understand what you mean when you say "the experiments are still confidential". What experiments are you talking about? I am quite familiar with the invention and functioning of the transistor; it's not a secret. —Keenan Pepper 19:40, 2 August 2009 (UTC)

Last word: what we know now like theory are just presumtions. NOBODY saw the electrons and holes. They just assumed there should be something like this. All we know is deduction science, not the real thing. Someone will invent another theory in future, maybe, a new theory answering more question than the actual one. Still the new one it will not be for sure a valid one. So, why to talk about holes ?

Pair generation / recombination asymmetrical ?

There is still no clear explanation of what exactly is asymmetrical. Diffusion is symmetrical so it cannot be the explanation. Why is the double layer depleted of carriers, if carriers can be produced via electron-hole pair generation? Is it that the process of pair generation-recombination in the double layer is nonlinear with respect to the applied voltage? Is it similar to the charge transfer on the electrode surface?

Forward and Reverse Bias illustrations

I think diagrams illustrating the effect of turning on forward and reversed bias would be helpful in understanding the physics; especially helpful would be electron/hole energy vs. position diagrams. Zylorian (talk) 01:45, 4 January 2010 (UTC)

Methods of making PN junctions -- dubious tag discussed

I just put a 'dubious' tag on the unsourced statement that a pn junction can be made from two separate pieces (of p-type and n-type material). Can't put my finger on a source right now, but it used to be said often that a crystal structure in common (and either free of crystal defects or *very* close-to) was needed for a semiconductor junction, not just electrical contact. OTOH a recent 'rm' edit taking away text about 'commonly' producing the junctions by alloying (not common now, even though common a long time ago) seems correct for current technology: alloying was a usual method of making germanium junction transistors in days gone by, but that was replaced by silicon wafer/diffusion technology. Terry0051 (talk) 16:11, 8 January 2010 (UTC)

Maybe the answer is at begining of this article.

Čikić Dragan (talk) 19:57, 11 March 2010 (UTC)

I modified the article to avoid saying that anyone would ever build a p-n junction with two separate semiconductor crystals, but did mention polycrystaline silicon solar cells. The alloy junction transistors and diodes that used to be made of germanium sort of used more than one crystal; the crystal structure melted near the indium that was placed on the germanium surface, and as the sample cooled, the crystal regrew. So there was new crystal material introduced, but it was aligned at the atomic level with the existing crystal. Jc3s5h (talk) 04:09, 12 March 2010 (UTC)

The potential barrier cannot be made zero and currents for various forward bias voltages

The potential barrier of a pn junction can never be brought down to zero ….nor ever “reversed”, however strong the forward biasing voltage. The question then arises: where does the applied voltage drop ? Will it be possible to include the following numerical to illustrate the point ? Consider a silicon p-n junction with doping concentrations N_A = 2.5 x 10¹⁵ cm^-3 and N_D = 5 x 10¹⁶cm^-3 at 300°K with the intrinsic concentration n_i = 1.5 x 10¹⁰.(Problem in Electronic Devices and Circuits by Milman and Halkias). Using the formula for current I = I_o(e^V/V_T -1), we obtain V_o = 0.703 Volts at 300°K and I_o = 9.17 x 10^-13 Amps. Using the formula for current I = I_o(^eV/V_T -1), we obtain for a forward bias V of 0.6V, V_T = 0.026 V at 300ºK or 27ºC, current I = 10.45 mAmps. What we observe here is that a forward bias voltage of 0.6 V which is less than V_o = 0.703 V has caused a current of 10mA in the diode. For a forward bias voltage 0.69V < V_o = 0.703V, we obtain I = 340 mAmps ! An increase in forward bias voltage of 0.09V has caused the forward current to increase by nearly 330 mAmps and the bias voltage is yet less than the barrier potential. With V = 0.702V < 0.703V (V_o), I = 0.5 Amps ! If a small diode, it will surely burn out with this current ! We assumed that the applied voltage appears across the junction entirely ignoring the voltage drops across the bulk of the p and n regions. It is reasonable to assume that, yet, as the applied voltage approaches Vo = 0.703V, and the current increases, some voltage will begin to drop across the bulk p and n regions and the resistance of the ohmic contacts to uphold the current conservation law and only a small part of the applied voltage lowers the barrier potential V_o. Therefore, the current will begin to level off before a current of 0.5 amps flows. Sridhar Chitta Sridhar10chitta (talk) 00:46, 8 March 2010 (UTC)

The potential barrier calculation was 0.76V was in error and is changed to 0.703V. Accordingly the forward current calculation at 0.759V is changed to 0.702 volts and is now 0.5 amps in place of 4.8amps.Sridhar10chitta (talk) 14:31, 28 August 2010 (UTC)

electron and holes density in the charged regions around the junctions

Not being an expert in semiconductor physics, I'm not sure, but I strongly suspect the figure A.A might not be accurate. Because electrons can recombine with holes, right? Therefore I'd expect that when you enter the charged region near the junction coming from the P side, hole density would start to decrease before electron density increases, or at least, hole density would decrease faster than electron density increases. In fact I suspect that most electrons coming to the P side from the N sides would recombine with one of the holes they find on their way. Same goes for holes crossing the junctions from the P side to the N side, I'd expect most of them to recombine with an electron from the N side. Thus, the first thing you'd see when you get closer to the junction from either side is a decrease of the majority carrier, not an increase of the minority carrier.ThorinMuglindir (talk) 20:39, 7 July 2012 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: page moved. Vegaswikian (talk) 00:52, 3 January 2012 (UTC)

---

P-n junction → P–n junction – Since this article has been moved twice before without discussion, I am initiating a formal move request because this article does not contain standard punctuation. I believe that Headbomb was correct, and that the hyphen should again be replaced with an en dash. In English, the en dash is usually used instead of a hyphen in compound (phrasal) attributives in which one or both elements is itself a compound, e.g. public-school–private-school rivalries, or p-type semiconductor–n-type semiconductor junction. Per MOS:DASH, when naming an article, do not use a hyphen as a substitute for an en dash that properly belongs in the title, for example in Eye–hand span. To aid searching and linking, provide a redirect from the corresponding article title with hyphens in place of en dashes, as in Eye-hand span. The move will be consistent with metal–semiconductor junction, which already uses an en dash in the title. I also note that the article text, including the boldface title in the lead, already uses en dashes. Wbm1058 (talk) 18:34, 27 December 2011 (UTC)

Past moves

• 04:40, 26 May 2009 User:Headbomb moved P-n junction to P–n junction ‎ (dash)
• 21:33, 27 November 2009 User:Mauls moved P–n junction to P-n junction over redirect ‎ (Hyphen, not n-dash)

Poll and discussion

• Support if you mean put the en-dash character in the title, as p–n junction, not the html code. Dicklyon (talk) 03:45, 28 December 2011 (UTC)
  • There is no difference between the character and the html code (though I also prefer to use the character). The reason I changed it is because the RM bot (for whatever reason) cannot read the character properly, but can read the html. Jenks24 (talk) 04:01, 28 December 2011 (UTC)
    • Is it important to change things to make it easier for bots to read? I thought this encyclopedia was written for people to read, not bots. --Wtshymanski (talk) 18:52, 28 December 2011 (UTC)
      • HIs point is that it doesn't affect readers; and we don't have to use the code except to make this RM bot happy. I thought that wasn't a problem, but maybe my experience is obsolete there. Dicklyon (talk) 18:58, 28 December 2011 (UTC)
• Support. Endash used in article. Change warranted under WP:MOS: junction of p with n. Glrx (talk) 18:11, 28 December 2011 (UTC)
• Support. --JorisvS (talk) 16:26, 30 December 2011 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.