Quantum Film Might Replace CMOS Sensors 192
An anonymous reader writes "Quantum film could replace conventional CMOS image sensors in digital cameras and are four times more sensitive than photographic film. The film, which uses embedded quantum dots instead of silver grains like photographic film, can image scenes at higher pixel resolutions. While the technology has potential for use in mobile phones, conventional digital cameras would also gain much higher resolution sensors by using quantum film material." The original (note: obnoxious interstitial ad) article at EE Times adds slightly more detail.
Finally a film replacement? (Score:3, Interesting)
Can the speed be adjusted like ISO 100-400 etc?
Don't care about more pixels (Score:3, Interesting)
In particular: (Score:3, Interesting)
According to the articles, both.
In particular:
- It replaces the in-chip photodetector with an on-top-of-chip detector, allowing all the real estate on the chip be used for the REST of the system rather than reserving most of it for light sensors. That means you can use bigger features (and cheaper processes) - and/or get more pixels by shrinking the features back down a bit.
- It gives about a 4x sensitivity improvement. (2x because the quantum dots are more sensitive, another 2x because they get to be on top (so the light isn't attenuated by chip structures) and cover the whole pixel rather than part of it.) You can use that to make 4x more sensitive pixels of the same size, 4 times more pixels of the same sensitivity, or some other tradeoff.
Re:Doesn't mean much as long as the optics still s (Score:2, Interesting)
If the sensor gets small enough, the lens can be something other that a refractive solid. Perhaps a drop of liquid in some sort of electrostatic suspension, where problems with the material are far less, and the lens can be focused by reshaping rather than moving.
Re:Night vision goggles (Score:5, Interesting)
> With enough sensitivity everything gives off infrared radiation...
Actually it does so with no sensitivity at all, just by being hotter than absolute zero. However, to detect infrared your sensor must not only be sensitive to it, it must also be significantly colder than the object you are trying to image. otherwise it will just detect its own emissions.
Re:Doesn't mean much as long as the optics still s (Score:4, Interesting)
As an engineer who does astronomical optics rather than a photographer, I can say with certainty with absolute certainty that all else being equal (i.e. diffraction limited case) a larger aperture is sharper. This is simply a matter of physics. The resolution is inversely proportional to diameter of the aperture due to the wave-like nature of light.
Now, if by 'crisper' you don't mean sharper, but rather a fuzzy measure of how you think it looks, its not surprising because smaller lenses of good quality are easier to make, and will thus approach the ideal diffraction limit. But this isn't a case of all other things being equal, and won't be as capable.
Re:They're black! (Score:4, Interesting)
If you point any of those cameras toward the sun, you will see flare. This is carefully explained in the video. To suppress flare, you need to stop reflections. On the glass, you can multilayer coatings. On the sensor, you can't do that. So you have to live with the reflection. If you have a concave lens element facing toward the camera body, you have a little concave mirror just waiting to reflect the specular reflection of the sun back onto your sensor. If the new sensors are black, they are not going to reflect much - so less flare.
What TFS/TFS doesn't mention is... (Score:2, Interesting)
This material has a tunable band-gap by using different combinations and ratios of S, Pb, Cu, Ti, Cd, Hg, Te, Ag, etc. Silicon sensors and their exotic equivalents have fixed, and very limited band-gaps. Additionally silicon based sensors have a rather limited quantum efficiency which is about 40% to 50% efficient under idea configurations. CMOS imagers are anything but idea configurations.
OmniVision's innovation of using BSI didn't increase their efficiency to 80%, it reduced the number of photons absorbed by interfering metalization. area over front-side illuminated solutions... under ideal conditions. This is where the 40% - 50% efficiency numbers come from, and they cannot say so with a straight face because the trenching around the sensor's pixels reduced the coverage over the array... increasing the gaps between pixels.
With this new material they get increased conversion efficiency from the material and increased active area within the pixel with the first-surface configuration. (the metal area is hidden under the photo-sensitve layer, with no trenching. With the tunable band-gap they also get to target IR solutions with sensitivity to wave lengths >1000nm. Si can't do that at all. With other tunings they get improved visible light sensitivity.
While the material is far more toxic than silicon-only solutions, it is a lot cheaper to deposit. Don't eat the film and you should be fine :)