No idea.

For many kinds of them, yes, but not literally all

There have been some improvements but their poor stability is still the biggest problem yeah

I often see developement in that area. Mostly from this channel. Maybe that impacts it's other uses. https://youtu.be/Lglick8bCPc

If it's a moving mirror camera* and it's used to take stills it's probably fine, as the sensor is only exposed for a fraction of a second per image.
If you want to film with it or put it in a phone, where it's exposed all the time, it would certainly not be enough.

* I have no clue what they are called in english

Digital single-lens reflex, aka DSLR if that's what you mean by moving mirror

I've heard there's been some real breakthroughs in perovskite for solar cells in just the last few years. As you said, chemical instability is supposed to be their primary weakness, but my understanding is that progress has been made in finding the perfect chemical makeup for the "sandwiching" materials between layers of perovskite. I'm pretty sure that "perfect" chemical makeup is the proprietary trade secret variety, so I don't really know much more about it.

And admittedly, I've never been in the field of materials science, so you're much more of an expert in this area. But I've been following a lot of green energy news, and I know promising progress is actively being made on perovskite.

I mean, lead is a very common element and can have many legitimate uses. If we're talking about using some amount of lead in a camera sensor, do understand how tiny camera sensors are. This is likely a very insignificant amount of lead. And it will be fused into this sensor, it's not likely to ever leave the confines of the component's plastic casing, behind a lens, with a phone. That's very different from say, mixing it into gasoline and burning it.

Thanks. I have to admit I haven't worked on perovskite since then, so my knowledge is surely very outdated.

I found this paper that seems so address this question:

https://www.sciencedirect.com/science/article/abs/pii/S0026265X23005428
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perovskites demonstrate exceptional photodetection abilities characterized by high sensitivity and fast response times, rendering them ideal for the development of optical sensors for medical diagnostics and environmental monitoring. Additionally, they hold promise in gas sensing applications, detecting specific gases with high sensitivity and opening up a wide range of potential applications in industrial process control and environmental monitoring. Although perovskite materials have gained attention due to their unique properties, their stability in the presence of moisture or oxygen remains a significant challenge and is an active area of research.
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this study provides a comprehensive evaluation of recent applications of perovskite materials-based sensors. Specifically, the focus is on chemiresistive gas sensors based on perovskite oxides and fluorescence/photoelectrochemical sensors based on halide perovskites

This is actually a really good paper, but i'm skimming it to find the references to the stability of peroskite...but i'm not good at doing this on a mobile device.