Solar cells, also known as photovoltaic (PV) cells, are devices that convert sunlight directly into electricity. I remember doing experiments with solar cells that were included in the electronic project kits I had growing up.
The history of solar cells dates back to the early 19th century when French physicist Alexandre-Edmond Becquerel (March 24, 1820 – May 11, 1891) observed the photovoltaic effect in 1839. Becquerel studied the solar spectrum, magnetism, electricity, and optics, and is also known for his work in luminescence and phosphorescence. His son, Henri Becquerel, is one of the discoverers of radioactivity.
In 1839, at age 19, experimenting in his father’s laboratory (Antoine César Becquerel[1]), Edmond created the world’s first photovoltaic cell.
In this experiment, silver chloride or silver bromide was used to coat the platinum electrodes; once the electrodes were illuminated, voltage and current were generated. Because of this work, the photovoltaic effect has also been known as the “Becquerel effect”. It was not until the mid-20th century that the practical applications of solar cells were realized.
1830-1948 Timeline – from Wikipedia
- 1839 – Edmond Becquerel observes the photovoltaic effect via an electrode in a conductive solution exposed to light.
- 1873 – Willoughby Smith finds that selenium shows photoconductivity.
- 1874 – James Clerk Maxwell writes to fellow mathematician Peter Tait about his observation that light affects the conductivity of selenium.
- 1877 – William Grylls Adams and Richard Evans Day observed the photovoltaic effect in solidified selenium, and published a paper on the selenium cell. ‘The action of light on selenium,’ in “Proceedings of the Royal Society, A25, 113.
- 1883 – Charles Fritts develops a solar cell using selenium on a thin layer of gold to form a device giving less than 1% efficiency.
- 1887 – Heinrich Hertz investigates ultraviolet light photoconductivity and discovers the photoelectric effect
- 1887 – James Moser reports dye-sensitized photoelectrochemical cell.
- 1888 – Edward Weston receives patent US389124, “Solar cell,” and US389125, “Solar cell.”
- 1888–91 – Aleksandr Stoletov creates the first solar cell based on the outer photoelectric effect
- 1894 – Melvin Severy receives patent US527377, “Solar cell,” and US527379, “Solar cell.”
- 1897 – Harry Reagan receives patent US588177, “Solar cell.”
- 1899 – Weston Bowser receives patent US598177, “Solar storage.”
- 1901 – 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).
- Einstein’s “On a Heuristic Viewpoint Concerning the Production and Transformation of Light” was published in Annalen der Physik in 1905.
- 1904 – George Cove Solar electric generator.
- 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 produces a method to grow single crystals of metal. Decades later, the method is adapted to produce single-crystal silicon.
- 1921 – Einstein was awarded the Nobel Prize in Physics for his work on the photoelectric effect.
- 1932 – Audobert and Stora discover the photovoltaic effect in Cadmium selenide (CdSe), a photovoltaic material still used today.
- 1935 – Anthony H. Lamb receives patent US2000642, “Photoelectric device.”
- 1941 – Russell Ohl files patent US2402662, “Light sensitive device.”
- 1948 – Gordon Teal and John Little adapt the Czochralski method of crystal growth to produce single-crystalline germanium and, later, silicon.
In the 1950s, practical applications of solar cells began to emerge, with the development of silicon-based photovoltaic technology. Since then, solar cells have become increasingly efficient and affordable, and their use has grown dramatically, particularly in recent years as the need for clean, renewable energy sources has become more urgent. Bell Laboratories realized that semiconducting materials such as silicon were more efficient than selenium.
They managed to create a solar cell that was 6 percent efficient. Inventors Daryl Chapin, Calvin Fuller, and Gerald Pearson (inducted to the National Inventors Hall of Fame in 2008) were the brains behind the silicon solar cell at Bell Labs. While it was considered the first practical device for converting solar energy to electricity, it was still cost-prohibitive for most people. Silicon solar cells are expensive to produce, and when you combine multiple cells to create a solar panel, it’s even more expensive for the public to purchase.
Mohamed M. Atalla developed the process of silicon surface passivation by thermal oxidation[2] at Bell Laboratories in 1957. The surface passivation process has since been critical to solar cell efficiency. He was an Egyptian-American engineer, physicist, cryptographer, inventor, and entrepreneur. He was a semiconductor pioneer who made important contributions to modern electronics.
He is best known for inventing the MOSFET (metal–oxide–semiconductor field-effect transistor, or MOS transistor) in 1959 (along with his colleague Dawon Kahng).
In 1958, the U.S. Signal Corps Laboratories creates n-on-p silicon solar cells, which are more resistant to radiation damage and are better suited for space. In 1959, Hoffman Electronics creates 9% efficient solar cells. Vanguard I, the first solar-powered satellite, was launched with a 0.1 W, 100 cm2 solar panel.
In 1960 Hoffman Electronics creates a 14% efficient solar cell and in 1962, the Telstar communications satellite is powered by solar cells. In 1963, the Sharp Corporation produces a viable photovoltaic module of silicon solar cells, and in 1964 the satellite Nimbus I is equipped with Sun-tracking solar panels.
In 1967, the Soyuz 1 is the first manned spacecraft to be powered by solar cells. Akira Fujishima discovers the Honda-Fujishima effect[3] which is used for hydrolysis in the photoelectrochemical cell in 1967. The next year, in 1968, Roger Riehl introduces the first solar-powered wristwatch. The early 1970s saw Salyut 1 and Skylab powered by solar cells. The world’s first building (in New Mexico) was heated and otherwise powered by solar and wind power exclusively in 1974.
The Solar Energy Research Institute is established in Golden, Colorado in 1977. In 1978 the first solar-powered calculators are introduced such as the Royal Solar 1, Sharp EL-8026, and Teal Photon. The 1980s was a decade of significant progress for solar cells, as new technologies were developed and the cost of production decreased. During this period, amorphous silicon solar cells were introduced, which were less expensive to produce and had higher efficiency than previous types of thin-film solar cells.
Additionally, new materials and manufacturing techniques were developed that improved the efficiency and reliability of crystalline silicon solar cells. In 1984, the world’s first solar-powered airplane, Solar One, was successfully flown, demonstrating the potential for solar energy to be used in transportation.
The following year, the first solar-powered car, the Sunraycer, won the World Solar Challenge race across Australia. The 1980s also saw increased government support for solar energy, with the creation of incentives and policies aimed at promoting the use of renewable energy.
This led to a boom in the solar industry, with companies such as SolarWorld and SunPower being founded during this time. In the 1990s, there was a major push to make solar power more affordable, with governments around the world offering subsidies and incentives to encourage the adoption of solar technology.
This led to a boom in the solar industry, with the cost of solar panels falling dramatically over the last few decades. Today, solar power is becoming an increasingly important part of the global energy mix, with the International Energy Agency predicting that solar energy will become the largest source of electricity by 2035.
The development of new technologies, such as perovskite[4] solar cells, could further increase the efficiency and affordability of solar power, making it an even more attractive alternative to traditional energy sources.
Footnotes
- Antoine César Becquerel (March 7, 1788 – January 18, 1878) was a French scientist and a pioneer in the study of electric and luminescent phenomena. In 1820, following the work of René Just Haüy, he found that pressure can induce electricity in every material, attributing the effect to surface interactions (this is not piezoelectricity). In 1825 he invented a differential galvanometer for the accurate measurement of electrical resistance. In 1829 he invented a constant-current electrochemical cell, the forerunner of the Daniell cell. [Back]
- Silicon surface passivation by thermal oxidation is a technique used to reduce the number of defects on the surface of silicon wafers, which can negatively affect the performance of electronic devices made from them. The process involves heating the silicon in an oxygen-rich environment, which causes a thin layer of silicon dioxide to form on the surface. This oxide layer acts as a barrier, preventing impurities from diffusing into the silicon and reducing the recombination of charge carriers, which can improve the efficiency of solar cells and other electronic devices. Silicon surface passivation by thermal oxidation is a widely used technique in the semiconductor industry and has been shown to improve the performance of a range of devices. [Back]
- The Honda-Fujishima effect, also known as the Fujishima-Honda effect, is a phenomenon in which titanium dioxide (TiO2) photo-catalytically decomposes water into hydrogen and oxygen when exposed to ultraviolet light. The effect was first observed by Akira Fujishima and Kenichi Honda at Tokyo University in 1972 and has since become an important area of research for its potential applications in the fields of renewable energy and environmental remediation. The Honda-Fujishima effect has been used to develop photocatalytic materials that can break down organic pollutants, such as those found in wastewater, and produce hydrogen gas as a clean energy source. [Back]
- Perovskite is a type of mineral that has a specific crystal structure, named after Russian mineralogist Lev Perovski. In recent years, perovskite materials have gained significant attention in the field of materials science due to their unique electronic, optical, and mechanical properties. They have been used in various applications, including photovoltaics, optoelectronics, and catalysis. Perovskite solar cells, in particular, have been the subject of intense research due to their high power conversion efficiency and low cost of production. However, there are still challenges that need to be overcome, such as stability issues and toxicity concerns. Overall, perovskite materials have the potential to revolutionize various industries and contribute to the development of sustainable technologies. [Back]
Further Reading
Sources
- “Solar Cell” Wikipedia
- “Antoine César Becquerel.” Encyclopædia Britannica. Encyclopædia Britannica, Inc., n.d. Web. 29 Apr. 2023.
- “Antoine César Becquerel.” The Editors of Encyclopaedia Britannica, Encyclopedia Britannica, 12 Nov. 2020, https://www.britannica.com/biography/Antoine-Cesar-Becquerel
- “The History of Solar.” Solar Power Authority, 2 Aug. 2017, https://www.solarpowerauthority.com/the-history-of-solar/.
- “A Brief History of Solar Energy.” Solar Energy Industries Association, n.d., https://www.seia.org/solar-industry/research-resources/brief-history-solar-energy.
- “Solar Photovoltaics: The Cheapest Source of Electricity in History.” International Energy Agency, 28 Sept. 2020, https://www.iea.org/reports/solar-photovoltaics
- M. M. Al-Jassim, S. Ghanbari, S. S. Hegedus, “Silicon Surface Passivation by Thermal Oxidation for Photovoltaic Applications: A Review,” IEEE Journal of Photovoltaics, vol. 2, no. 2, pp. 128-134, Apr. 2012.
- S. S. Hegedus, J. M. Gee, C. H. Cousins, “Surface Passivation of Solar Cells Using Thermal Oxidation,” Journal of Vacuum Science and Technology A, vol. 8, no. 6, pp. 3912-3917, Nov. 1990.
- A. Fujishima and K. Honda, “Electrochemical Photolysis of Water at a Semiconductor Electrode,” Nature, vol. 238, no. 5358, pp. 37-38, Apr. 1972.
- M. Anpo, “Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results,” Chemical Reviews, vol. 113, no. 6, pp. 4,390-4,959, May 2013.
- H. Matsumura and K. Kamimura, “Photovoltaic systems for residential use in Japan,” IEEE Transactions on Energy Conversion, vol. 3, no. 1, pp. 89-94, Mar. 1988.
- B. S. Richards and M. A. Green, “Solar cell technology in the 80s,” Progress in Photovoltaics: Research and Applications, vol. 1, no. 1, pp. 3-12, Jan. 1993.
- “A Brief History of Solar Energy,” Solar Energy Industries Association, https://www.seia.org/solar-industry/research-resources/brief-history-solar-energy.
