1839 Property of photovoltaics discovered by French scientist Edmund Becquerel while observing conductivity of metal electrodes when exposed to light.
1877 W.G. Adams and R.E. Day noticed the photovoltaic effect on solid selenium, and created the first selenium solar cell.
1887 Heinrich Hertz noticed the photoelectric effect, and published his paper entitled “On an Effect of Ultraviolet Light upon the Electric Discharge.” He noticed that the spark created at a receiving electric circuit increased when ultraviolet light hit the negative terminal.
1904 Albert Einstein published his revolutionary paper on the photoelectric effect, explaining its behaviour. This also set the stage for the quantum theory of light (involving photons). Both the photoelectric effect and the quantum theory of light are important to solar cells.
1914 Junction layer in PV cells observed.
1916 Milikan’s experiments proved photoelectric effect.
1953 Dr. Dan Trivich, Wayne State University, made the first theoretical calculations of the efficiencies of various materials of different band gap widths based on the spectrum of the sun.
1954 Photovoltaic cells with conversion efficiencies of 6% were first designed by RCA and Bell Laboratories, with applications in aerospace.
1955 Hoffman Electronics sold their commercial PV cell with 2% efficiency for $25 each.
  E.D. Jackson proposed increased efficiency by using multiple-layered cells.
1958 First PV-powered satellite, Vanguard I (US), was launched, and operated for eight years.
1973 One of the earlier PV-powered homes was produced by University of Delaware.
1976-77 NASA LeRC used PV cells to power refrigerators, electric cars, lookout towers, water coolers, highway signs and insect traps.
1981 One of the first PV-powered airplanes, Solar Challenger, flew.
1985 In Australia, a team led by Martin Green first produced silicon cells achieving 20% efficiency. They used lasers to carve grooves in the cell surface, increasing performance.
1986 Arco Solar produced first thin-film PV cell.
1996 In Germany, the solar plane Icare flew, powered by some 3000 super-efficient PV cells.