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Perovskite-based image sensors promise higher sensitivity and resolution than silicon (techxplore.com)
submitted 1 year ago by to c/technology@lemmy.world
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They use stacked transparent color sensors, like Foveon camera sensors used to.

In numerous experiments, the researchers put the two prototypes, which differ in their readout technology, through their paces. Their results prove the advantages of perovskite: the sensors are more sensitive to light, more precise in color reproduction and can offer a significantly higher resolution than conventional silicon technology.

The fact that each pixel captures all the light also eliminates some of the artifacts of digital photography, such as demosaicing and the moiré effect.

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[–] 28 points 1 year ago* (8 children)

I used to work on hybrid perovskite for solar cells, during my PhD, a few years ago. The problem with theses materials was their short lifetime (some thousands of hours of sun exposition) and chemical instability, which made them unsuitable for "real life" uses, back then (but suitable to get high impact-factor papers...). Is that still a problem?

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  • [–] 8 points 1 year ago (1 child)

    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.

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  • [–] 5 points 1 year ago (1 child)

    Does it matter if there's a ultraviolet and IR filter on it? Is it functionally equivalent to darkness?

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  • [–] 2 points 1 year ago

    No idea. IIRC the problem comes from chemical instability i.e., even when properly encapsulated, the methylammonium just evaporates/decompose and you're left with a nice lead iodide layer. Can't say if it's better now. It's been quite a feew years ago.

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  • [–] 4 points 1 year ago (2 children)

    Isn't thousands of hours enough for many cameras?

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  • [–] 7 points 1 year ago (3 children)

    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

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  • [–] 1 point 1 year ago (1 child)

    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.

    You can say goodbye to live view then

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  • [–] 3 points 1 year ago (1 child)

    Silicon CCDs have lifetime exposure limits also. Perovskites are delicate and 1000 hours is way less than the millions silicon offer, but its also overkill in a still camera. Lenses wear out faster than silicon tech does.

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  • [–] 1 point 1 year ago (3 children)

    I had just watched a video about they need lead as well? Is that true?

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  • [–] 2 points 1 year ago

    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.

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  • [–] 1 point 1 year ago

    I found this paper that seems so address this question:

    https://www.sciencedirect.com/science/article/abs/pii/S0026265X23005428 // 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. // 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.

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