RE: STM New Sensor?7 Dec 2023 22:30
Yes, lee7, it's been pointed out on here before that the VD55G1 is likely to use QDs since the QE/MTF of 55% at 940 is consistent with what Jonathan Steckel has said can be achieved with QDs. Otherwise the sensitivity of silicon without them is more like 25-30%.
What is unclear is to what extent the other consumer sensors ST has in the design stage use QDs. They don't give numbers for quantum efficiency but they say things like "outstanding performance in the NIR region". My view is that there's a very good chance they use QDs too, partly because that would be consistent with outstanding NIR performance and also because the dates of their design fit in with ST's design of QD devices.
The VD56G3 is particularly interesting. ST are using that sensor in the under OLED biometrics tech they have devised with Trinamix. I think that was a first gen version of that sensor, but if you look at the documentation it was heavily updated on 23 November, just a couple of weeks after Nanoco shipped their first dots. Could just be a coincidence.
If the sensors are using QDs then it begs the question why the documents/specs don't say so. One reason could be that they don't want competitors to realise that they are using QDs. That said, Jonathan Steckel has given several presentations on it. Alternatively they may not want to advertise the used of lead in the dots.
It's all a bit unclear, so much so that I don't think it's worth speculating on too much (forgive this essay). Que sera sera, whatever sensors are eventually using them.