
New Sensor a Thousand Times More Sensitive Than Current Camera Sensors - morphics
http://www.sciencedaily.com/releases/2013/05/130530094624.htm
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e12e
Apparently this is a 1000x improvement over previous _graphene_ sensors -- not
ccds and such in general:

[http://www.nature.com/ncomms/journal/v4/n5/full/ncomms2830.h...](http://www.nature.com/ncomms/journal/v4/n5/full/ncomms2830.html)

"Graphene has attracted large interest in photonic applications owing to its
promising optical properties, especially its ability to absorb light over a
broad wavelength range, which has lead to several studies on pure monolayer
graphene-based photodetectors. However, the maximum responsivity of _these_
photodetectors is below 10 mA W−1, which significantly limits their potential
for applications. Here we report high photoresponsivity (with high
photoconductive gain) of 8.61 A W−1 in pure monolayer graphene photodetectors,
about three orders of magnitude higher than those reported in the literature,
by introducing electron trapping centres and by creating a bandgap in graphene
through band structure engineering. In addition, broadband photoresponse with
high photoresponsivity from the visible to the mid-infrared is experimentally
demonstrated. To the best of our knowledge, this work demonstrates the
broadest photoresponse with high photoresponsivity from pure monolayer
graphene photodetectors, proving the potential of graphene as a promising
material for efficient optoelectronic devices."

(My emphasis)

With thanks to these comments which helped point me in the right direction:

[http://tech.slashdot.org/comments.pl?sid=3809257&cid=438...](http://tech.slashdot.org/comments.pl?sid=3809257&cid=43888645)

[http://www.reddit.com/r/technology/comments/1fefup/graphene_...](http://www.reddit.com/r/technology/comments/1fefup/graphene_camera_sensors_said_to_be_1000_times/ca9hra8)

I was also under the (apparently correct) assumptions that current digital
sensors are close to the theoretical limits (because of the number of photons
available for sampling).

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secabeen
Yep. Current digital sensors at maximum sensitivity are measuring in the
single-digit numbers of photons per photosite. They can't get much better.

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Bud
Given that existing high-end CCD sensors already have sensitivity to
_individual photons_ , I very much doubt that this new graphene sensor can
beat that technology by three orders of magnitude. I don't think the laws of
physics will allow for three orders of magnitude more improvement in this
area.

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mtrimpe
Are we seriously there already? We really are living in amazing times.

Do you happen to have a link to some sources about this?

~~~
Bud
Sure, here are a few:

[http://www.princetoninstruments.com/cms/index.php/news/8-top...](http://www.princetoninstruments.com/cms/index.php/news/8-top-
stories/222-emiccd)

<http://iopscience.iop.org/0953-4075/42/11/114011>

[http://www.andor.com/learning-academy/astronomy-an-
overview-...](http://www.andor.com/learning-academy/astronomy-an-overview-of-
andors-solutions-for-astronomy)

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Filligree
I wonder how this translates to ISO sensitivity at a given quality level.

Certainly a 1000x improvement seems unlikely, most of the noise is electrical,
but even the 10x improvement you'd expect from lower voltages would be
amazing.

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yummybear
I wonder how this will impact astronomy. I assume more energy efficient also
means less need for cooling, possibly leading to cheaper low-noise sensors?

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jacquesm
I don't think that's a given. Just like more energy efficient transistors
(smaller, fewer atoms) are more susceptible to noise.

~~~
ygra
Certain types of image sensor noise is quite directly affected by temperature.
An increase of 5–10 K usually doubles the dark current, for example.

~~~
jacquesm
Yes, of course it is affected by temperature. But the thinner the substrate
could upset the signal/noise ratio faster than the gain in cooling capacity
would correct for it.

The same happens in most sensors on the extremes of sensitivity, and cooling
is actually a way to correct for some of that. For space based sensor pods
cooling is usually the limiting factor for long term deployment.

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arunitc
Does this mean I'll be able to get the same image, which I currently shoot at
a shutter speed of 1 second, at 1/1000 of a second?

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zamalek
This is awesome. Why doesn't it surprise me at all? I can't see what they can
use graphene for next.

Does anyone know if graphene photo-sensors carry residual charge (the reason
CCDs and CMOSs capture noise)?

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Gravityloss
Interesting but the signal to noise ratio might be a more important metric?
Maybe it's too early to say much about that?

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tlarkworthy
Wow that was developed cheap ($200k)

