Quantum Technology for new camera sensors

[Pete Ferling]

http://www.wired.com/gadgetlab/2010/03/quantum-dot-images/

[BJL]

http://www.wired.com/gadgetlab/2010/03/quantum-dot-images/

Quantum dot technology for sensors might bring some advantages, but it is being overhyped, especially by that headline claim about "cellphone cameras good enough to use for wedding photos", and there are a few other false or highly misleading statements from the rep's of InVisage Technologies.

Some facts:
- recent back-side illuminated sensors (starting to be used in digicams and phones) have QE of up to about 60% or 70%.
- DSLR sensors have QE of over 40%.

Thus the talk of a 4x improvement (which his specifically a claim of 4x higher QE) and the specific claim that "the silicon in current image sensors has a light-absorbing efficiency of only about 50 percent" is hard to understand. At best, comparisons are being made to less than state of the art alternatives, which makes no sense, since by the time any quantum dot sensor comes to market, the competition will be better than the current state of the art.

[Greg Campbell]

Well, they also mention the misc. circuitry and 'dead space' on the surface of conventional sensors as contributing to the increase in sensitivity.  Supposedly QD has no such obstructions.  Of course they are conveniently ignoring the micro-lenses that cover most modern sensors.    

Even IF their claims of 4X sensitivity are true, how the heck does that equate to MF quality from a typical 1/16" cell phone sensor?      

Greater dynamic range, or lower noise would be nice.  No mention of those issues.

Sounds like BS to me!

-Grumpy

[BJL]

Well, they also mention the misc. circuitry and 'dead space' on the surface of conventional sensors as contributing to the increase in sensitivity.

That is why I mentioned the high QE of Back-Side Illuminated (BSI) sensors, which have all that circuitry on the side of the sensor chip away from the incoming light, and so not blocking any of it. For example, Sony offers BSI in its EXMOR R sensors and Toshiba offers a BSI sensor for phone cameras, and phone camera major OmniVision is up to second generation in BSI:
http://www.sony.net/SonyInfo/technology/te...exmor_r_01.html
http://www.dpreview.com/news/0908/09080601sonycmos.asp
http://en.akihabaranews.com/25350/cameras/...-mobile-devices
http://www.photographyblog.com/news/omnivi...ixel_technolog/

Ignoring these well-known and currently available alternatives when discussing a technology that is over a year away from market is blatantly misleading.