Holes and other empty spaces

Status
Not open for further replies.

Thread Starter

Ratch

Joined Mar 20, 2007
1,070
mik3,

Holes are not particles. People think of them as particles to make thinks easier. A hole is just a place where an electron was before it leaves this place.
I gave this reference before, but I will do so again. From Volume I, Second Edition, Semiconductor Fundamentals by Robert F. Pierret and Gerold W. Neudeck. Footnote on page 30 "..Of prime importance is the drastic simplification resulting from the fact that the quantum-mechanical entities known as electrons and holes may be treated, both conceptually and mathematically, as classical particles." The book goes on to show that holes have an equivalent mass. Strange and mysterious things happen at the quantum level, such as the Heisenberg Uncertainly Principle, that have no macro world equivalent.

Because the electron is negative the hole is said to be positive.
I will let you explain why a hole is not considered neutral. After all, when you remove the electron, doesn't that make it neutral?

Ratch
 

studiot

Joined Nov 9, 2007
4,998
What is accepted by "most people" is not necessarily the truth. A consensus of opinion is not proof. Holes are not a concept, they are real. Remember the link I gave you to an authoritative source that said holes have just as much standing as electrons with respect to quantum-mechanical entities? Holes are a semiconductor phenomenon, and have an "effective mass" different from electrons. Holes even live in n-type semiconductors, although their numbers and lifetimes as minority carriers are much less the the majority electrons. Holes have a different mobility than electrons. You will never find a quantum hole in a metal wire because the ocean of electrons in metals will completely swamp a hole before it can ever form.
Actually I agree with Ratch's above statement.

However I don't understand where this thread is going. What are we discussing?

I don't see how one can make anything except the most passing reference to 'holes' without discussing Fermi levels, doping materials, conduction and valence bands and such.
In that world holes have a happy place.
 

mik3

Joined Feb 4, 2008
4,843
From the text you posted from the book:

"..Of prime importance is the drastic simplification resulting from the fact that the quantum-mechanical entities known as electrons and holes may be treated, both conceptually and mathematically, as classical particles."

It says that holes may be treated as particles. They are not particles but you can treat them as particles and give them properties for simplicity.

As, for the electron after you remove it you will be left with a positive charge or state it another way, with minus the electron's charge (which is negative). Imagine an atom with 2 protons and 2 electrons, it has a neutral charge. If you remove one electron the atom will become positively charged. The one electron which lacks is the so called hole.
 

Thread Starter

Ratch

Joined Mar 20, 2007
1,070
mik3,

It says that holes may be treated as particles. They are not particles but you can treat them as particles and give them properties for simplicity.
Well, if something waddles like a duck, quacks like a duck, eats like a duck, and defecates like a duck, then what is it? Like I said before, quantum mechanics makes strange things happen.

As, for the electron after you remove it you will be left with a positive charge or state it another way, with minus the electron's charge (which is negative). Imagine an atom with 2 protons and 2 electrons, it has a neutral charge. If you remove one electron the atom will become positively charged. The one electron which lacks is the so called hole.
Right you are, the unmovable core of the atom supplies the positive charge.

Ratch
 

thingmaker3

Joined May 16, 2005
5,083
Galileo.

True, but he was a good example of the majority being wrong. His knowledge and experience with respect to astronomy was correct, and the majority including the Pope were not.
You commit the logical fallacies of dicto simplicitor and argumentum ad vericundium. Possibly also argumentum ad antiquiatatum, depending on why exactly you cite Galileo.

m4yh3m,

Who are you refering to m4yh3m, and how are they going off topic?

Ratch
He is referring to YOU, Ratch. You went off topic in the diode thread by choosing to argue quantum physics instead of choosing to help the OP of that thread. This is why all these posts are now in the "off topic" area.

Well, if something waddles like a duck, quacks like a duck, eats like a duck, and defecates like a duck, then what is it?
We are not discussing ducks. Ducks and the particles of which they are composed have mass. What is the mass of a hole?
 
Last edited:

Thread Starter

Ratch

Joined Mar 20, 2007
1,070
thingmaker3,

You commit the logical fallacies of dicto simplicitor and argumentum ad vericundium. Possibly also argumentum ad antiquiatatum, depending on why exactly you cite Galileo.
Can you put it into English and explain what it means? I don't reply to you in a foreign language.

He is referring to YOU, Ratch. You went off topic in the diode thread by choosing to argue quantum physics instead of choosing to help the OP of that thread. This is why all these posts are now in the "off topic" area.
Then why doesn't he explain to whom he is talking about and specifically why. Why do you have to front for him?

I invite your attention to the beginning of of the thread http://forum.allaboutcircuits.com/showthread.php?t=16680&highlight=diode . In the very first post, the OP himself asks a question about holes. So it was not off topic. Holes are a quantum physics phenomenon which I kept as simple as possible.

We are not discussing ducks. Ducks and the particles of which they are composed have mass. What is the mass of a hole?
Everything physical has mass. I used a popular phrase to make a point. The first couple of sentences of this link give you a rough idea of what effective mass is. One can expect electrons to have it, but holes have it too.

http://en.wikipedia.org/wiki/Effective_mass

Ratch
 

thingmaker3

Joined May 16, 2005
5,083
Can you put it into English and explain what it means? I don't reply to you in a foreign language.
http://www.csun.edu/~dgw61315/fallacies.html Enjoy.

I used a popular phrase to make a point.
Nope. Sorry. You don't let other folk do that, so I'm not letting you do it. Fair is fair.

Then why doesn't he explain to whom he is talking about and specifically why.
He does. He does so eloquently and with no ambiguity. You just ignore it.
Why do you have to front for him?
I don't. I just object strongly to your attempt to hide from his words.

I invite your attention to the beginning of of the thread http://forum.allaboutcircuits.com/showthread.php?t=16680&highlight=diode . In the very first post, the OP himself asks a question about holes. So it was not off topic. Holes are a quantum physics phenomenon which I kept as simple as possible.
The OP asked about THE BASIC OPERATION OF DIODES. The OP also identified themselves as a STUDENT TRYING TO UNDERSTAND NEW CONCEPTS. Your condescending attitude and your diatribe on hole flow -vs-electron flow were absolutely off topic. Your complicated tirades were very off topic. Your dredging up of dead horse issues was extremely and offensively off topic. As a courtesy to you, and especially to those who responded to you, I moved them all here rather than simply deleting them.

The following is addressed to persons other than Ratch:
Did I perhaps choose the wrong course of action? Should these condescending diatribes simply be deleted in the future? Or edited heavily to remove the condescension? (Ratch: I know your opinion on this. Let other folk speak, if you please.)

As to the holes themselves, you say in one post (http://forum.allaboutcircuits.com/sh...01&postcount=1) "holes have effective mass, in another (http://forum.allaboutcircuits.com/sh...1&postcount=21) "holes have an equivalent mass" and finally (in the post preceeding this one) "everything physical has mass."

So, are you saying that holes are physical? Or only that they are "effectively physical?" In other words, are you backing yourself into another corner (in which case you'll pull another of you dodges) or are you about to launch into another flurry of defining the definition of "definitive?"

Let's see you do some REAL pedantry, Ratch. Let's see you prove conclusivley the electron flow model to be invalid!!!
 

beenthere

Joined Apr 20, 2004
15,819
Or, as I have asked in the past, describe exactly how a transistor may be controlled by voltage. Let's select a 2N3053 as the exemplar transistor.
 

steveb

Joined Jul 3, 2008
2,436
Or, as I have asked in the past, describe exactly how a transistor may be controlled by voltage. Let's select a 2N3053 as the exemplar transistor.
Transistors are rarely directly controlled by voltage without some type of feedback or compensation. This is because the transistor equations actually respond to Vbe/VT not Vbe itself. Hence, it would be too temperature sensitive. This is one arguement against saying that a transistor is only a voltage controlled device. What about temperature? Temperature could be used to control a transistor even though it is usaully not practical to do so.

Two simple examples of voltage control are (1) the current mirror circuit and (2) a transistor drive with a base voltage with a large emitter resistor.

With the current mirror, the output current is provided by a transtor whose base-emitter voltage is directly provided by a diode voltage. However, the diode voltage is generated by driving the diode with current, in order to allow for temperature compensation. This is voltage control with compensation.

If a transistor is driven by a voltage on the base with a large emitter resistor. The emitter resistor acts as a voltage feedback for the base emitter voltage on the transistor. This is voltage control using voltage feedback.

It can also be argued that transistors that appear to be controlled by current are really controlled by voltage with feedback. It's all a matter of how you model the system. Voltage controlled models tend to be more complicated since they are usually nonlinear. (actually current control models are nonliear too, but they are closer to being linear and are better approximated by linear models)

It is silly to argue over whether a transistor is voltage or current controlled. It's all on how you view it, and what model you use. The main issue I see is that many people think the transistor is a simple current amplifier with a constant gain. This myth should be dispelled, but otherwise a current control model with varying Beta (Hfe) is perfectly fine.
 
Last edited:

steveb

Joined Jul 3, 2008
2,436
Also, not only is it silly to argue over whether transistors are current controlled or voltage controlled. It's silly to argue over whether anything is a particle or not. Have we all forgotten about the wave-particle duality principle from our physics classes?

Newton and Huygens were arguing about this centries ago. It's all about how you want to look at it, and what model you want to use.
 

beenthere

Joined Apr 20, 2004
15,819
That was a nice example, steveb. But we have been looking for such a response from Ratch for some time.

The position he apparently holds is that the current control model is totally incorrect, and utterly invalid. The following is a quote from an earlier thread:
The BJT is a voltage controlled creature, whose base current is a by-product or waste product of the forward bias of the emitter-base junction. The real control comes from the emitter-base voltage which controls the injection of charge carriers into the depletion region and onwards to the collector. It just happens that the base current is proportional to the collector current, but the base current is irrelevant to the control of the collector current.
But several of us have been looking for any example at all that both proves his case (nothing but voltage control) and disproves the other (current control). We have yet to see such proof. You may notice from the above that the assertion is absolute; modeling producing one result or the other is not predicted. The key phrase is "real control", which means that nothing else is a valid mechanism for controlling a BJT.
 

studiot

Joined Nov 9, 2007
4,998
Temperature could be used to control a transistor even though it is usaully not practical to do so.
I did actually give an example of an everyday use of temperature control of a transistor in the thread on transitor action.

However I thought from the title at least, that this thread was about holes?????????????????

and in particular a more in-depth treatment than suitable for a beginner just meeting a PN junction.

Isn't that why it was separated off?
 
Last edited:

Thread Starter

Ratch

Joined Mar 20, 2007
1,070
thingmaker3,

Thanks for the link. Just what I needed. A cheat sheet for the Latinisms you like to throw around. In the future, don't forget to link those terms to my deeds. And it would also be nice if you criticized others with the same rigor that you do to me, not that I mind.

Nope. Sorry. You don't let other folk do that, so I'm not letting you do it. Fair is fair.
I have no idea what you mean. Can you provide an example?

He does. He does so eloquently and with no ambiguity. You just ignore it.
Simple, elequently, and false. The OP requested the information about holes. If fact, he devoted almost a whole paragraph requesting information. I did not go off on a wild tangent to nowhereville as m4yhem asserts. Read the OP's first post again.

I don't. I just object strongly to your attempt to hide from his words.
I have not and did not hide from anything. You should know that by now. I could have let it pass, but I did not. Doesn't that tell you something?

The OP asked about THE BASIC OPERATION OF DIODES. The OP also identified themselves as a STUDENT TRYING TO UNDERSTAND NEW CONCEPTS. Your condescending attitude and your diatribe on hole flow -vs-electron flow were absolutely off topic. Your complicated tirades were very off topic. Your dredging up of dead horse issues was extremely and offensively off topic. As a courtesy to you, and especially to those who responded to you, I moved them all here rather than simply deleting them.
No, if the OP was asking about holes in a diode, then he was asking about something a little bit above its basic operation. And he did ask specifically about holes.

On of the reasons for being a student is trying to understand new concepts. How does that relate to this discussion?

Condescending and diatribe is in the eye of the beholder. You should be more concerned as to whether the facts I presented were true or false.

Dead horse issues? I reviewed the thread again, and as far as I could see, all my "irrelevant" replies were to other members who brought the issues up. Perhaps you should look at the live horses in your own pasture more closely.

Thank you for your courtesy.

The following is addressed to persons other than Ratch:
Did I perhaps choose the wrong course of action? Should these condescending diatribes simply be deleted in the future? Or edited heavily to remove the condescension? (Ratch: I know your opinion on this. Let other folk speak, if you please.)
By all means, how can I prevent it?

As to the holes themselves, you say in one post (http://forum.allaboutcircuits.com/sh...01&postcount=1) "holes have effective mass, in another (http://forum.allaboutcircuits.com/sh...1&postcount=21) "holes have an equivalent mass" and finally (in the post preceeding this one) "everything physical has mass."
The correct term is "effective mass". I miswrote the word , and I apologize for the confusion. As far as "everything physical has mass", I believe it to be a statement of fact. Can you think of an example where that does not apply?

So, are you saying that holes are physical? Or only that they are "effectively physical?" In other words, are you backing yourself into another corner (in which case you'll pull another of you dodges) or are you about to launch into another flurry of defining the definition of "definitive?"
At the quantum level? I have a hard time believing it myself. But I quoted Pierret and Neudeck earlier, and they write "both conceptually and mathematically, electron and holes can be treated as classical particles, as long as the carrier effective mass replaces the particle mass in mathematical relationships". Then I used the duck phrase to infer that holes at the quantum level are "effectively physical" because electrons certainly are. You can argue as to whether it is true or not, but the conclusion does have plausibility.

Let's see you do some REAL pedantry, Ratch. Let's see you prove conclusivley the electron flow model to be invalid!!!
What electron flow model and in what context? That seems to be tall order, because many proofs and applications exist which show that electrons do indeed flow.

Ratch
 

Thread Starter

Ratch

Joined Mar 20, 2007
1,070
beenthere,

Or, as I have asked in the past, describe exactly how a transistor may be controlled by voltage. Let's select a 2N3053 as the exemplar transistor.
And as been explained previously, the equations are in Sedra and Smith. Also it was explained that trying to control an exponential relationship of Vbe and Ic for a Vbe range of 0 to 1 volt or so is not practical. Therefore resistance in series with Vbe is used to swamp Vbe and convert the signal from a voltage to a current. This can be explained by feedback analysis.

Ratch
 

Thread Starter

Ratch

Joined Mar 20, 2007
1,070
beenthere,

That was a nice example, steveb. But we have been looking for such a response from Ratch for some time.
Then you have not read post #113 of http://forum.allaboutcircuits.com/showthread.php?t=12378&highlight=transistors&page=12 where I write that The various transistor models used work just fine for determining what a transistor does and how it interacts with other elements within a circuit. They do not provide much insight on why transistors do what they do.

The position he apparently holds is that the current control model is totally incorrect, and utterly invalid. The following is a quote from an earlier thread:
Quote:
The BJT is a voltage controlled creature, whose base current is a by-product or waste product of the forward bias of the emitter-base junction. The real control comes from the emitter-base voltage which controls the injection of charge carriers into the depletion region and onwards to the collector. It just happens that the base current is proportional to the collector current, but the base current is irrelevant to the control of the collector current.
Incorrect with respect to the concept how and why a transistor works, not how it can be applied to a circuit. Of course the base current has to be taken into account in a practical circuit. And since it is proportional to Ic within a certain range, that information can be used for circuit design and application models. I never said otherwise. But no matter how you drive a transistor in its active region, it is controlled by its Vbe.

Ratch
 

beenthere

Joined Apr 20, 2004
15,819
I see no control here. How do I build a differential amplifier using BJT's will only voltage as the control. We must specifically exclude current here, as we do keep hearing that BJT's are voltage controlled.

Following that, I will ask for a linear power supply regulator, and so on. Surely you can demonstrate that voltage is the sole controlling parameter in each case?

By the way, what is a definition of "waste product", with reference to Ib? How may we eliminate it?
 
Status
Not open for further replies.
Top