"Smoking Gun" - finally!

[tinu]

http://en.wikipedia.org/wiki/Diode
The Shockley ideal diode equation  or the diode law is derived with the assumption  that the only processes giving rise to current in the diode are drift (due to electrical field), diffusion, and thermal recombination-generation. It also assumes   that the recombination-generation (R-G) current in the depletion region is insignificant. This means that the Shockley equation doesn’t account for  the processes involved in reverse breakdown and photon-assisted R-G. Additionally, it doesn’t describe the  â€œleveling off” of the Iâ€"V curve at high forward bias due to internal resistance.

There are many more assumptions, although subtler. Approximations are different. Need a reference? http://www.thefreedictionary.com/approximation
Anyway, this is basics in solid-state physics. You really didn’t know it or just pretended for the sake of your unborn but beloved child?

Now, please don’t throw with math if you don’t know what’s behind equations. As you say it is ‘dirty stuff’ and although I do not agree, I’d add it really pollute physics when missused, as one can see.
Still a diode cooling itself to 0K (thermal insulated, obvious to everyone although apparently not to you) is something nature stubbornly refuses to amaze us.

It’s pointless to go on. I’m out and hand waving.
But good luck, anyway!

Cheers,
Tinu

[PaulLowrance]

Where's your math? 

http://en.wikipedia.org/wiki/Diode
The Shockley ideal diode equation  or the diode law is derived with the assumption  that the only processes giving rise to current in the diode are drift (due to electrical field), diffusion, and thermal recombination-generation. It also assumes   that the recombination-generation (R-G) current in the depletion region is insignificant. This means that the Shockley equation doesn’t account for  the processes involved in reverse breakdown and photon-assisted R-G. Additionally, it doesn’t describe the  â€œleveling off” of the Iâ€"V curve at high forward bias due to internal resistance.

Your above text is a quote from wikipedia. There's no assumption about the diode equation. I am using Schottky diodes, and it would be incorrect to say that it's an *assumption* the RG current is insignificant. In terms of Schottky diodes, it is a fact. Please read about Schottky diodes and recombination -->
http://en.wikipedia.org/wiki/Schottky_diode

It is not included in the equation because it is so insignificant. Like I said, it is an *approximation*, not an *assumption*.  There's no assuming the RG is insignificant in my Schottky diodes. It's a fact.

There are many more assumptions, although subtler. Approximations are different. Need a reference? http://www.thefreedictionary.com/approximation

There are countless known effects. Inductance is an example. Gravity is another example. Tinu, they are insignificant. All physics equations are approximations. It would require an encyclopedia to write down a mathematical equation that considered every single thing that effected the diode. The same applies to the laws of thermodynamics. So what? If you know of a more accurate semiconductor equation then by all means show us. Including RG in the equations is not going to make any difference in terms of diodes rectifying thermal noise.


So where's your math showing how a diode will handle the thermal energy? Physics is not about being 100% perfect. There is no such thing as the *prefect* 100% accurate equation-- as stated, not in semiconductor math or thermodynamics math.  It makes no difference in the result. Diodes rectify thermal energy. It is a know experimental fact that thermal energy causes noise current through the diodes depletion region. So if the diode equation predicts 5e-6 amps, and if you include RG current to make it say 5.00001e-6 amps, then so what? The noise current still flows through the diode. The diode is still a dynamic resistor.


PL

[PaulLowrance]

To sum this up, what tinu is saying is pointless. It goes without saying that no mathematical model considers every known effect. Gravity has an effect on the diode. So what?

Tinu has not shown any mathematics that predicts diode behavior with thermal noise. He cannot improve upon the present small signal diode modeling mathematics. It is well known that the recombination and generation in Schottky diodes is insignificant.  Virginia diodes performed measurements on their zero bias diode that clearly shows the diode produces thermal noise in agreement with the predicted values. Sorry tinu, but it's a known fact thermal AC noise current is continuously flowing in a passive diode all by itself. There's your AC noise current. There's your rectification resulting in a DC potential. It's a known fact that the diodes dynamic resistance changes with any change in current-- diode square law. I've verified the diode square law a bit below 1uV, where the diode showed no signs of magically switching from rectification to zero rectification. The diode square law is a live and well. The rectification is relative to the square of the AC noise.

If you doubt a diode does not produce AC noise, then read up, because it was proven with the Virginia Diodes Inc. diode -->

http://www.virginiadiodes.com/VDI/pdf/VDI%20Detector%20Char%20ISSTT2007.pdf


AC current flows through diodes due to thermal noise. The diode square law is well proven to rectify noise below 1uV.  The total Johnson noise, AC, flowing through my SMS7630 diodes @ RT is equal to the kTC noise, which is sqrt(k 300 / 0.14p) = 172 uV.

PL

[wm_carr]

Just wondering... Could these diodes be made by screenprinting?

[PaulLowrance]

I don't see why not, but I've never heard of screenprinting being used for semiconductor fabrication. The common method is to use an ultra thin coating photoresist that is spun on the wafer. Then UV light that shines through a mask lifts the photoresist, which is easily removed. And from there, either deposition or etching is performed.

IMO the photoresist route is a bit much for a low budget garage project, which is why I propose a somewhat older method of using the mask in combination with deposition. You can see an animation I created -->

Watch carefully, as the animation actually changes, albeit at a slow rate:
http://greenselfreliantenergy.com/forum/index.php?topic=18.msg90#msg90

PL