That chart is one of the variants of a chart published and maintained by NREL, the US National Renewable Energy Laboratory: https://www.nrel.gov/pv/cell-efficie

That chart is one of the variants of a chart published and maintained by NREL, the US National Renewable Energy Laboratory: https://www.nrel.gov/pv/cell-efficiency.html https://www.nrel.gov/pv/cell-efficiency.html Interactive version: https://www.nrel.gov/pv/interactive-cell-efficiency.html https://www.nrel.gov/pv/interactive-cell-efficiency.html NREL's website has a lot of good stuff if you're interested in renewable energy.