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This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 January 2022 and 18 March 2022. Further details are available
on the course page. Student editor(s):
Ryjn,
Bazabache (
article contribs).
I think that image could be better. I don't think having multiple gaps all over the place really helps explain it. -- User:Dgrant
I just realized that I think I might have deleted some significant chunks in my recent edit of the Band gap article. I just finished reading the Wikipedia most common faux pas, and apparently is it not good to delete lots of material. -- User:Dgrant
I'm actually wondering now if that figure is even correct at all. Did you get it from a source, or draw it yourself? It might actually be good to show one of those classic figures where they show the difference between a metal, insulator, and semiconductor, insofar as the bandgap. -- User:Dgrant
I think this statement is a bit vague: "In many devices this kind of conductivity is undesirable, and larger bandgap materials give better performance". I think we should say, "In a <blank> device, this kind of conductivity is better..." where <blank> is an example of one of these devices. -- User:Dgrant
Just a couple of nit-picky points I would like to make. The first one is that I'm confused as to who we are aiming the article at. You explain that "e" is the exponential "function" yet just state chemical formulae (GaAlAs etc.) without explanation. If you assume the target reader is newbie enough to not know what "e" means in the expression, they are unlikely to know what some of those chemicals are. Secondly, this phrase seems to make no sense to me whatsoever: "Conductivity is undesirable, and larger band gap materials give better performance." Conductivity is what makes, for example, the internet possible. I fail to see how conductivity can therefore be undesirable! That sentence needs either removing or a big revision to make clear exactly what is meant, particularly making reference to what situations high conductivities are undesirable. I understand that some people will find some of this very nit picky, but it's something I've picked up from my project supervisor! :P Lateralis 19:49, 12 October 2006 (UTC)
"The only available carriers for conduction are the electrons which have enough thermal energy to be excited across the band gap,"
Is this correct? It is my understanding that the conductivity of intrinsic semiconducter material is due to thermally generated electron-hole pairs so that the charge carriers are an equal number of electrons (in the conduction band) and holes (in the valence band). Alfred Centauri 16:20, 26 May 2005 (UTC)
how do we knows emiter and collecter of a transister?
It would be really nice if someone would explain where the band gap arises from. It has something to do with the periodic potential (in the free electron model it disturbs the free-electron energy band -> bragg reflection creates the bonding and antibonding states at the edges of brillouin zones and the energy gap is the "area" between bonding- and antibonding state energies at the edge) but why aren't there any quantum states in the gap? Would be really helpful. Sorry for my english, hope you can understand :) --Risto 28.1-- Tiresais 17:13, 18 July 2006 (UTC)0, 2005
to Risto; the bandgap is the electron-conductance of material as defined by its atomic structure,
where:
e (-Eg/kT)
e is the exponential function Eg is the band gap energy k is Boltzmann's constant T is temperature
Electron transfer is dependant upon two points material band gap and temperature.
Please would someone good at editing tables add the band gap for cubic boron nitride to the table of band gaps. Thanks DFH 17:11, 29 August 2006 (UTC)
Done. Maaf 23:31, 21 February 2007 (UTC)
The definition provided here is incomplete, as it only refers to the definition of band gap as it relates to semiconductor physics. Band gaps also refer to any particle or quasiparticle, not just electrons. For example, photons (see photonic crystal) and phonons both exhibit band gaps for certain materials. I suggest the definition be altered to
See Google's scholarly articles for phononic or photonic crystals. -- h2g2bob 20:53, 21 February 2007 (UTC)
@ 2007-02-22T00:38Z
I've removed the big table of band gaps ( diff). It was unsourced - so there is no way of knowing if it is accurate or even if it is a copyright violation. -- h2g2bob 18:25, 25 February 2007 (UTC)
Got my answer here instead. http://hyperphysics.phy-astr.gsu.edu/Hbase/Solids/band.html —Preceding unsigned comment added by 70.248.200.212 ( talk) 01:19, 22 April 2008 (UTC)
I agree. The above link is more useful than this wiki page. As for this wiki page; sometimes no information is more useful than poor information. At least if there were no page here, maybe someone who knew the theory well would think to him/herself, "No one has done anything here, maybe I should..." Eliasds ( talk) 03:12, 28 April 2008 (UTC)
Which is the band gap for infrared light ?. And for ultraviolet ? -- Nopetro ( talk) 13:35, 20 May 2009 (UTC)
why does it say it's the energy difference between the bottom of the valence band and top of the conduction band in the intro, but it reverses top and bottom in the first paragraph of "in semiconductor physics"? —Preceding unsigned comment added by 99.121.57.249 ( talk) 00:14, 26 October 2010 (UTC)
The population of states here is described with Maxwell Boltzmann, but we are talking about electrons/holes. Therefore, shouldn't it be Fermi-Dirac statistics? That also connects directly to why the Fermi-level's probability of being filled is 1/2. — Preceding unsigned comment added by 141.14.132.20 ( talk) 10:55, 19 May 2016 (UTC)
Should we have a paragraph on LEDs since there is one on Photovoltaic cells ? If so perhaps also the table of band gaps could note which are direct or indirect, and possibly any major applications of the material eg LEDs or PV cells ? - Rod57 ( talk) 19:02, 29 October 2016 (UTC)
yes — Preceding unsigned comment added by 60.166.73.238 ( talk) 08:38, 6 February 2017 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||||||||||||
|
This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 January 2022 and 18 March 2022. Further details are available
on the course page. Student editor(s):
Ryjn,
Bazabache (
article contribs).
I think that image could be better. I don't think having multiple gaps all over the place really helps explain it. -- User:Dgrant
I just realized that I think I might have deleted some significant chunks in my recent edit of the Band gap article. I just finished reading the Wikipedia most common faux pas, and apparently is it not good to delete lots of material. -- User:Dgrant
I'm actually wondering now if that figure is even correct at all. Did you get it from a source, or draw it yourself? It might actually be good to show one of those classic figures where they show the difference between a metal, insulator, and semiconductor, insofar as the bandgap. -- User:Dgrant
I think this statement is a bit vague: "In many devices this kind of conductivity is undesirable, and larger bandgap materials give better performance". I think we should say, "In a <blank> device, this kind of conductivity is better..." where <blank> is an example of one of these devices. -- User:Dgrant
Just a couple of nit-picky points I would like to make. The first one is that I'm confused as to who we are aiming the article at. You explain that "e" is the exponential "function" yet just state chemical formulae (GaAlAs etc.) without explanation. If you assume the target reader is newbie enough to not know what "e" means in the expression, they are unlikely to know what some of those chemicals are. Secondly, this phrase seems to make no sense to me whatsoever: "Conductivity is undesirable, and larger band gap materials give better performance." Conductivity is what makes, for example, the internet possible. I fail to see how conductivity can therefore be undesirable! That sentence needs either removing or a big revision to make clear exactly what is meant, particularly making reference to what situations high conductivities are undesirable. I understand that some people will find some of this very nit picky, but it's something I've picked up from my project supervisor! :P Lateralis 19:49, 12 October 2006 (UTC)
"The only available carriers for conduction are the electrons which have enough thermal energy to be excited across the band gap,"
Is this correct? It is my understanding that the conductivity of intrinsic semiconducter material is due to thermally generated electron-hole pairs so that the charge carriers are an equal number of electrons (in the conduction band) and holes (in the valence band). Alfred Centauri 16:20, 26 May 2005 (UTC)
how do we knows emiter and collecter of a transister?
It would be really nice if someone would explain where the band gap arises from. It has something to do with the periodic potential (in the free electron model it disturbs the free-electron energy band -> bragg reflection creates the bonding and antibonding states at the edges of brillouin zones and the energy gap is the "area" between bonding- and antibonding state energies at the edge) but why aren't there any quantum states in the gap? Would be really helpful. Sorry for my english, hope you can understand :) --Risto 28.1-- Tiresais 17:13, 18 July 2006 (UTC)0, 2005
to Risto; the bandgap is the electron-conductance of material as defined by its atomic structure,
where:
e (-Eg/kT)
e is the exponential function Eg is the band gap energy k is Boltzmann's constant T is temperature
Electron transfer is dependant upon two points material band gap and temperature.
Please would someone good at editing tables add the band gap for cubic boron nitride to the table of band gaps. Thanks DFH 17:11, 29 August 2006 (UTC)
Done. Maaf 23:31, 21 February 2007 (UTC)
The definition provided here is incomplete, as it only refers to the definition of band gap as it relates to semiconductor physics. Band gaps also refer to any particle or quasiparticle, not just electrons. For example, photons (see photonic crystal) and phonons both exhibit band gaps for certain materials. I suggest the definition be altered to
See Google's scholarly articles for phononic or photonic crystals. -- h2g2bob 20:53, 21 February 2007 (UTC)
@ 2007-02-22T00:38Z
I've removed the big table of band gaps ( diff). It was unsourced - so there is no way of knowing if it is accurate or even if it is a copyright violation. -- h2g2bob 18:25, 25 February 2007 (UTC)
Got my answer here instead. http://hyperphysics.phy-astr.gsu.edu/Hbase/Solids/band.html —Preceding unsigned comment added by 70.248.200.212 ( talk) 01:19, 22 April 2008 (UTC)
I agree. The above link is more useful than this wiki page. As for this wiki page; sometimes no information is more useful than poor information. At least if there were no page here, maybe someone who knew the theory well would think to him/herself, "No one has done anything here, maybe I should..." Eliasds ( talk) 03:12, 28 April 2008 (UTC)
Which is the band gap for infrared light ?. And for ultraviolet ? -- Nopetro ( talk) 13:35, 20 May 2009 (UTC)
why does it say it's the energy difference between the bottom of the valence band and top of the conduction band in the intro, but it reverses top and bottom in the first paragraph of "in semiconductor physics"? —Preceding unsigned comment added by 99.121.57.249 ( talk) 00:14, 26 October 2010 (UTC)
The population of states here is described with Maxwell Boltzmann, but we are talking about electrons/holes. Therefore, shouldn't it be Fermi-Dirac statistics? That also connects directly to why the Fermi-level's probability of being filled is 1/2. — Preceding unsigned comment added by 141.14.132.20 ( talk) 10:55, 19 May 2016 (UTC)
Should we have a paragraph on LEDs since there is one on Photovoltaic cells ? If so perhaps also the table of band gaps could note which are direct or indirect, and possibly any major applications of the material eg LEDs or PV cells ? - Rod57 ( talk) 19:02, 29 October 2016 (UTC)
yes — Preceding unsigned comment added by 60.166.73.238 ( talk) 08:38, 6 February 2017 (UTC)