I'd be interested in seeing the optical spectrograph of the LEDs. If you want to simulate sunlight you want a full-spectrum LED like a Samsung LM301 series LED which are popular in grow lights. Not all LEDs are created equal, and even the LEDs in many "grow" lights only show two sharp peaks at red and blue wavelengths. A full-spectrum LED will output colors across the visible spectrum of light. You can't tell by looking at them, so you can either buy ones from which you trust the manufacturer or do what I did and build a cheap optical spectroscope using a raspberry pi with a small camera attached, a spectroscope lens, and some python code. I'm sure there are guides you can find with a quick web search if interested in making one.
This is covered by the CRI95+ value, note that the LM301 you mentioned only has a color rendering index of 70. Maybe it has predominant wavelengths that are relevant for plant growth, I don't know, but a CRI of 70 isn't impressive at all.
For an accurate rendering of the suns spectrum you basically would like to simulate the spectrum of a blackbody radiator with a surface temperature of 5500°C minus the absorption bands of water vapors, atmospheric gases thst are typically inbetween the sun and us. Also note that the suns spectrum extends both above and below the visible range, which gives you the feeling of warmth (infrared) and tan/sunburn (ultraviolet).
In reality most commercially available LEDs still have a extremely spikey spectrum compared to sunlight — this can be somewhat fixed by mixing different LED types and adding filters. But this is only done in extremely expensive movie lights like Arri skypanels.
Thanks for the insight. Most of what I know about LEDs, and specifically the LM301 series, comes from research I did prior to setting up a small indoor grow tent several years ago. It was a "spikey spectrum" precisely that I was trying to avoid. For growing Cannabis you do want spikes at red and blue, but better LEDs also emit a wider spectrum along with the spikes and that results in a better result. Having only spikes at red and blue alone works, but not as well. The lights I ended up buying had LM301H EVO LEDs with a CRI of 80 and were designed for a 2'x2' tent. You can also get LM301H LEDs with a CRI of up to 90, though. The lights I ended up buying only cost 80 BezosBucks at the time. I don't spend BezosBucks anymore, though, due to enshittification of everything Amazon, but I digress.
While they aren't designed for growing, and to use them would be a complete waste of $8k, I bet the Arri SkyPanel S120-C SoftLight with a CRI of 95 would do a fine job for growing. You weren't kidding about them being extremely expensive.
The LED datasheet has Typical normalized power vs. wavelength graph (figure 1h) https://otmm.lumileds.com/adaptivemedia/832eef99dd3139f98fa9...