They demonstrated their solar panel by using it to power a small toy Ferris wheel and a solar powered radio transmitter. After making some other improvements to the design, they linked together several solar cells to create what they called a “solar battery.”īell Labs announced the invention on Apin Murray Hill, New Jersey. They also found they were able to make good electrical contacts with the boron-arsenic silicon sells. To solve that problem, they tried different impurities, and eventually settled on arsenic and boron, which created a p-n junction that stayed near the surface. Another problem was that at room temperature, lithium migrated through the silicon over time, moving the p-n junction farther away from the incoming sunlight. One problem was the difficulty in making good electrical contacts with the silicon cells. The three then worked for several months on improving the properties of their silicon solar cells. Pearson, who was aware of Chapin’s work, went and told his friend not to waste any more time on selenium solar cells, and Chapin immediately switched to silicon. The ammeter jumped significantly, to their surprise. Pearson then hooked up an ammeter to the piece of silicon and shined a light on it. Pearson dipped it in lithium, creating a p-n junction. Fuller gave Pearson a piece of silicon containing gallium impurities.
Meanwhile, Calvin Fuller, a chemist, and Gerald Pearson, a physicist, were working on controlling the properties of semiconductors by introducing impurities. He tried selenium solar cells, but found them too inefficient. Chapin investigated several alternative energy sources, and settled on solar power as one of the most promising. In 1953, engineer Daryl Chapin, who had previously been working on magnetic materials at Bell Labs, was trying to develop a source of power for telephone systems in remote humid locations, where dry cell batteries degraded too quickly. The first practical silicon solar cell was created thirteen years later by a team of scientists working together at Bell Labs. Ohl patented his solar cell, which was about one percent efficient. When the cell is hooked up in a circuit, an incoming photon that hits the cell can then give an electron a kick and start current flowing. Excess positive charge builds up on one side of the p-n barrier, and excess negative charge builds up on the other side of the barrier, creating an electric field. Ohl had inadvertently made a p-n junction, the basis of a solar cell. This crack, which had probably formed when the sample was made, actually marked the boundary between regions containing different levels of impurities, so one side was positively doped and the other side negatively doped. He noticed that in this particular sample, current flowed through this sample when it was exposed to light.
#First solar roofs crack
He had been investigating some silicon samples, one of which had a crack in the middle. The next major advance in solar cell technology was made in 1940 by Russell Shoemaker Ohl, a semiconductor researcher at Bell Labs. Some research on selenium photovoltaics continued for the next several decades, and a few applications were found, but they were not put to widespread use. Though Fritts had hoped his solar cells might compete with Edison’s coal-fired power plants, they were less than one percent efficient at converting sunlight to electricity and thus not very practical. In 1883, American inventor Charles Fritts made the first solar cells from selenium. Several decades later, in 1873, Willoughby Smith, an English engineer, discovered the photoconductivity of selenium while testing materials for underwater telegraph cables. French physicist Alexandre-Edmond Becquerel, son of physicist Antoine Cesar Becquerel and father of physicist Henri Becquerel, was working with metal electrodes in an electrolyte solution when he noticed that small electric currents were produced when the metals were exposed to light, but he couldn’t explain the effect.
The story of solar cells goes back to an early observation of the photovoltaic effect in 1839. In April, 1954, researchers at Bell Laboratories demonstrated the first practical silicon solar cell. Solar cells, which convert sunlight into electrical current, had their beginnings more than a hundred years ago, though early solar cells were too inefficient to be of much use. Fuller at work diffusing boron into silicon to create the world's first solar cell
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