The chart I linked shows both upper atmosphere and sea level irradiance, for what it's worth. Though it's possible the chart simply isn't the most accurate. I only did casual research.
Doing more research, looking at [1] (the data source for that Wikipedia image), it looks like the peak is between 480 nm (cyan) and 540 nm (lime green) for "global tilt" and 480 nm to 580 nm (yellow) for "direct + circumsolar" (I have no idea what the difference is between "global tilt" and "direct + circumsolar").
Interesting. It seems like the chart in my original comment isn't as precise as I believed.
Doing more research, looking at [1] (the data source for that Wikipedia image), it looks like the peak is between 480 nm (cyan) and 540 nm (lime green) for "global tilt" and 480 nm to 580 nm (yellow) for "direct + circumsolar" (I have no idea what the difference is between "global tilt" and "direct + circumsolar").
Interesting. It seems like the chart in my original comment isn't as precise as I believed.
[1]: https://www.nrel.gov/grid/solar-resource/spectra-am1.5