photodiode voltage

That looks fun, Do you have any better links to a paper? Do they have to make some special diode structure or will any PIN work?

George H.

It sounds like there's some MOS version of SCR action going on. Potentially quite interesting if the claims are true, although of course very slow.

Cheers

Phil Hobbs

enjoy !

Thanks Dmitriy. GH

The manufacturer of your device is practicing safe specs.

Hi, I believe, that this is one of those photodiodes, acquired by Optodiodes as part of the portfolio when they acquired IRD. They were developed for X-ray and particle detection, and as standard sensors in such applications. IRD then told me that they are used by NIST. I used some other diode from SXUV series for detecting energetic electrons, those were for reverse bias voltage of above 50V. Worked smoothly, just according to the theory. And they are, of course, sensitive to UV and visible light. In the shown data sheet I don't like many things, but especially a package of Cd=1500pF, and tr=1ns at 50 Ohm. It didn't worked for me. Later on I used some Hamamatsu custom diodes, for the same application. They also worked well. You have to talk to any one of those R&D teams or application people and explain exactly your application and properties of what you want to see. I believe, they will find something appropriate and if it is a fairly large potential of doing business, they may tailor a custom diode for you. It is all a matter of depth and thickness of the depleted area, i.e. a junction.

The arithmetic of response is quite simple: particle energy minus 20% losses for backscattering (so called, as a QE of about 80%), then each 3.62 eV produces one electron-hole pair, which are collected by the reverse field. For electrons (and other particle detection) this mechanism is called as a bombardment gain. And it is the gain with a very low noise factor, which is a fano factor. If you need to shield them from other particles, e.g. photons, you may use a metal film of appropriate thickness on top of the active area. This is for custom part.

Large business potential may be replaced/exchanged by large NRE. :-)

Hi Pavel, thanks for the info. (If you included a bit of the text you were responding to, it would help in understanding your answer.)

I'm not sure I'd call one energetic electron making a bunch of e-h pairs 'gain' but I get what you mean. (I'm going to have to look up the Fano factor.) But as you say the number of e-h pairs is highly correlated with the electron energy... so not the random gain noise you get with (say) a PMT looking at single photons.*

George H.

That's why modern IC are made using masks.