Word: silicones
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Dates: during 1970-1979
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...heat water, which in turn heats home water systems. A basic series of units for a one-family home costs about $2,000 and saves only about $40 a year in fuel bills. The promising new frontier is photovoltaics, the direct conversion of sunlight into electricity by using silicon-crystal panels. Though the price of photovoltaic cells has been cut in half since 1975, the cost is still $9 per watt,*equal to a staggering $40,000 for a one-family home. Still, advances are being made in the efficiency of panels and methods to store power at night. Last...
...pools and home water systems. But the exciting side of the industry that is attracting the larger companies is photovoltaics?the direct conversion of sunlight into electricity. The theory is simple. A wafer-thin, 3-in. to 4-in. plate or "cell' that is sliced from a chemically treated silicon crystal will give off direct-current electricity when exposed to light. The amount that comes from each cell is minute, but many cells can be wired together in rooftop units to provide a maintenance-free, long-lasting, nonpolluting power source. During the day the cells simultaneously produce electricity and charge...
...intensify the sun's rays, the Los Angeles project would use parabolic and elliptical cells instead of flat ones. Arco Solar and other companies including Exxon, Mobil and Shell are working in intense rivalry and secrecy on such matters as improving storage batteries, finding better materials to substitute for silicon and even mass-producing flat "ribbons" of silicon to replace the present chunky and uneconomical crystals...
Miraculous as it may be, the tiny silicon "chip" that is at the heart of today's electronics revolution has certain drawbacks. Crammed with thousands of individual circuits and components, this computer-on-a-chip is only about a quarter the size of a thumbnail. Yet despite the minuscule dimensions of these circuits, the time required for electric current to traverse them places a limit on how speedily the little computer can make its calculations...
...make transistors and chips, scientists "dope" a semiconducting material ike silicon with impurities, creating regions that have either an excess or a deiciency of electrons-and thus are negatively (n zones) or positively (p zones) charged. If two n zones, say, are separated by a p zone, they act like an electronic switch, or transistor; a small voltage in the p zone controls fluctuations in the current flowing between the n zones. But every time an excess electron is released in the n zone to join the current flow, it leaves behind a positively charged spot. Because opposite charges attract...