1900-1929
- 1902 - Philipp von Lenard observes the variation in electron, energy with light frequency.
- 1904 - Wilhelm Hallwachs makes a semiconductor-junction solar cell (copper and copper oxide).
- 1905 - Albert Einstein publishes a paper explaining the photoelectric effect on a quantum basis.
- 1913 - William Coblentz receives US1077219, "Solar cell".
- 1914 - Sven Ason Berglund patents "methods of increasing the capacity of photosensitive cells".
- 1916 - Robert Millikan conducts experiments and proves the photoelectric effect.
- 1918 - Jan Czochralski, a Polish scientist, produces a method to grow single crystals of metal. Decades later, the method is adapted to produce single-crystal silicon.
- 1920s - Solar water-heating systems, utilizing "flat collectors" (or "flat-plate collectors"), relied upon in homes and apartment buildings in Florida and southern California.
Read more about this topic: Timeline Of Solar Cells