Related articles: Chapter 4: Logging into Windows XP Using RFID–Part I, Chapter 4: Logging into Windows XP Using RFID–Part II, Chapter 4: Logging into Windows XP Using RFID–Part III

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Aries Electronics, Inc.

<p>Solar-converted electricity costs two to three times as much to produce as energy generated from traditional sources. Inefficient energy conversion and the need to produce a very large number of wafers contribute to the high cost. Only about 16 percent of light that hits a solar cell wafer can be collected as usable electricity. To produce enough solar cells to generate 500 megawatts a year, a solar cell fab must produce as many as 400,000 wafers a day, an exponentially larger number than even the largest semiconductor plants produce. The cost of the silicon alone, not to mention the manufacturing costs, for that number of wafers is considerable. Improving the energy conversion efficiency, reducing the manufacturing costs and increasing the yield of silicon wafer-based solar cells are critical to the growth of the solar market.</p>

Related articles: Chapter 4: Logging into Windows XP Using RFID–Part I, Chapter 4: Logging into Windows XP Using RFID–Part II, Chapter 4: Logging into Windows XP Using RFID–Part III

Rittenhouse said Bell Labs continues to do fundamental research in wireless, networking, optics, computer science and still even in physics, but there we are focusing on quantum computation, high-speed electronics and nanotechnology with a group that is larger than the four I've seen reported in the media.

Admittedly, it is a much smaller group than before when we were doing silicon device research,” added Rittenhouse. We continue to have physical technologies research group and a physical sciences research group. In the past, they were divided into fundamental, materials science and device physics, but now they are focused on quantum computation, high-speed electronics and nanotechnology

RN60D2740FRSL_Vishay Dale_Through Hole Resistors

Bell Labs was once one of the shining stars of basic research in physics and even astronomy. Today, parent company Alcatel-Lucent has mandated that research be distributed among its cores businesses. Bell Labs is now organized into eight groups: physical technologies, computing technologies, optics, fixed access, wireless access, networking, service infrastructure and applications.

We still sponsor undirected research, but not as much as before. For instance, we don't do the astronomy work that we used to do. But now we focus our researchers in areas where we know they can be successful,” said Rittenhouse.

From our point of view, that was really always the case–we didn't study cosmic background radiation because we thought is was interesting physics, we studied it to improve satellite communications. It turned out we also solved an interesting physics problem, but that was not our intent.”

RN60D2740FRSL_Vishay Dale_Through Hole Resistors

Bell Labs most famous semiconductor breakthrough was the development of the transistor. In 1945, the Labs formed its Solid State Physics Group led by physicist William Shockley, whose mission was to develop an alternative to vacuum tube amplifiers. That groups developed the theoretical work of physicist Julius Edgar Lilienfeld, who filed the original patent on the transitor in 1925, but never developed the idea. Shockley, John Bardeen and Walter Houser Brattain are generally credited with the transistors invention, and were awarded the 1956 Nobel Prize for their pioneering work.

Today our mission is not that different from what is was before: We have always done and still do research that is scientifically important, but which is also relevant to the area of computation and communications” said Rittenhouse. Even for transistors, we didn't study them out of curiosity. We studied them because you can't make good telecom switches out of vaccum tubes.”

RN60D2740FRSL_Vishay Dale_Through Hole Resistors

Nevertheless, Bell Labs abandonment of basic research in IC materials and devices leaves the U.S. with one less semiconductor R&D center at a time when the pace on innovation is quickening and CMOS fabrication moves to advanced nodes beyond 45 nanometers. IBM Research (Yorktown Heights, N.Y.) is considered the leading fundamental semiconductor research facility left in the U.S. But Rittenhouse argued that it no longer makes sense for Bell Labs to compete with IBM in semiconductor research.

When Lucent had a semiconductor business that was coupled into selling communications chips, it was perfectly reasonable to have a semiconductor research group that focused on materials and devices,” said Rittenhouse. Even after the spinoff to Agere [Systems Inc., which merged with LSI Corp. last year], we kept the group going for six years just because it was doing very good physics and gave us another way of looking at communications problems. But now we have decided to move on, close that facility, and focus instead on fundamental work in networking, wireless and optics.”

There has always been a controversy over whether electroluminescence and photoluminescence involve the same states, so through comparisons using Raman scattering we have now proven that they both use the same states,” said Avouris.

IBM has also proposed a theory for how heat diverts energy from luminescence, thus reducing the efficiency of LENs. While further experimentation will be required to prove the theory, IBM claims it is now only a matter of time until virtually all wasted energy that formerly generated heat can be eliminated by changing the electronic structure of a device.

There are two types of emission from an object, radiative and nonradiative, with the latter being the energies lost by heat,” said Avouris. Radiative emission was always thought to be a fixed property of the material, but what we realized was that it is not only the material that is quantized–that has discrete states–but the photons also are part of a field that has quantized states.

Emission comes by coupling these two fields. We now feel that by using an electric field we can change the electronic structure of nanotubes so that heat cannot be generated,” he added.

Besides improving the efficiency of future devices by eliminating heat generation, IBM researchers also plan to experiment with methods of aligning nanotubes to a superlattice. This would allow an array of LENs to be fabricated on future silicon photonic chips.

Additionally, the MAX9938's low Vos allows the use of a lower full-scale Vsense voltage and, therefore, smaller Rsense resistor. The device thus minimizes voltage-drop loss in the line and power dissipation in the sense resistor, which otherwise could create a hot spot behind the LCD display of a notebook computer.

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