CPUs and GPUs account for more dollars spent than solar cells, but solar cells account for most area/mass of semiconductor devices made today.
A gigawatt of solar cells represents about 5 square kilometers of silicon wafers at 20% light conversion efficiency. The world installed 183 gigawatts of solar PV in 2021, almost all of it based on silicon wafers:
https://www.pv-magazine.com/2022/02/01/bloombergnef-says-glo...
That's in the neighborhood of 915 square kilometers of wafers.
Silicon for solar has risen meteorically over the past 20 years.
https://www.pv-magazine.com/2021/10/26/whats-next-for-polysi...
Until the early 2000s, demand for polysilicon (often simply referred to as “poly”) was dominated by the semiconductor industry, which required a fairly steady 20,000 to 25,000 metric tons (MT) per year. But semiconductor demand for poly was quickly outpaced by PV as the solar industry began to grow rapidly, from a rounding error at the turn of the millennium to almost half of global polysilicon demand by the middle of the decade.
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By the end of 2013, the manufacturing cost of polysilicon had tumbled to below $20/kg among industry leaders. Meanwhile, capacity had grown from less than 50,000 MT per year in 2007 to over 350,000 MT per year by 2013.
Polysilicon capacity at the end of 2021 was in the neighborhood of 700,000 metric tons, with more big expansions on the way. The extra 350,000 metric tons added since 2013 is almost entirely for solar.