At a $350 billion a year industry, the computer and semiconductor industry is not only among the largest manufacturing industries in the world, but also, arguably, the most important. Semiconductor technology has enabled the computing and communications revolution, the internet, the cell phone and more. PCs and cell phones continue to sell in growing numbers with even more powerful and more featured-packed devices on the drawing table, all of which will consume more and more powerful semiconductors. Devices that combine entertainment, mobile communications and computing are exploding onto the scene all of which are semiconductor-dependant. Along with that has come WiFi, WiMax and all the other communications that are convenient to use for communications through our cellular devices and computers. The Basics
Semiconductor is a material that has a resistivity value between that of a conductor and an insulator. The conductivity of a semiconductor material can be varied under an external electrical field. Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices. Semiconductor devices include the transistor, many kinds of diodes including the light-emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy. In a metallic conductor, current is carried by the flow of electrons. In semiconductors,current can be carried either by the flow of electrons or by the flow of positively-charged "holes" in the electron structure of the material.Silicon is used to create most semiconductors commercially. Dozens of other materials are used, including germanium, gallium arsenide, and silicon carbide. A pure semiconductor is often called an “intrinsic” semiconductor. The conductivity, or ability to conduct, of semiconductor material can be drastically changed by adding other elements, called “impurities” to the melted intrinsic material and then allowing the melt to solidify into a new and different crystal.
The Future
When physicists sandwiched together different types of semiconductor to create the first transistor in 1947, they made bulky vacuum valves obsolete and so revolutionised the electronics industry. Since then researchers have been pushing the boundaries of semiconductor technology hoping for another revolution. Progress towards ultra-high density magnetic recording, and a new branch of nanotechnology are some of the cutting-edge semiconductor research being conducted.
Nanotechnology is the science of making new materials - and structures like minute electronic devices less than one millionth of a metre big - atom by atom. Nanocrystals Technology in the USA have developed a structure known as a Quantum Confined Atom (QCA) believe they will become the building block for a range of new semiconductor devices.
A quantum confined atom is an atom or an ion (atom with an electric charge) trapped within a nanocrystal cage (a tiny cage made from the atoms of a semiconductor). In conventional semiconductor technology, most electronic devices are made from layers of different types of semiconductor. The semiconductor materials used are "doped" with atoms of different elements, which alter their properties so that each layer will have the particular electrical characteristics
needed for that type of device to work. QCA technology however is the direct opposite of this. Instead of the trapped atom altering the properties of its semiconductor host, the semiconductor atoms of the cage modify the properties of the atom they are confining.
Nanocrystals researchers are trapping atoms in spaces between 2 and 10 billionths of a meter in size. At present they are concentrating on trapping phosphorescent ions (ions that emit visible light of a certain colour when light of a different colour or invisible ultraviolet (UV) light is shone at them). By reducing the size of these cages from 10 down to between 2 and 5 billionths of a meter, the researchers found the ions could generate 20 times more light. This meant they were emitting as much light as conventional phosphor particles 1000 times larger. This dramatic enhancement of luminescence efficiency is expected to have an impact all optical devices such as light emitting diodes (LEDs), lasers, displays and fluorescent lamps and should be available commercially within five years. In fact, his nanophosphors could find their first application as early as next year, replacing existing phosphors that convert the X-rays used in medical imaging into light so a picture can be recorded. Because they are so small and efficient, the new nanophosphors can improve the resolution of X-ray images, and allow a smaller dose of X-rays to be used while still obtaining a clear picture. Today there is research being conducted to modulate and enhance other properties such as magnetic properties of the nanocrystals. This would mean QCAs could act as storage materials for data in ultra-high-density magnetic recording systems - all of which will soon be required by our computing devices such as, MP3 players, cell phones and laptops.
Nanotechnology is the science of making new materials - and structures like minute electronic devices less than one millionth of a metre big - atom by atom. Nanocrystals Technology in the USA have developed a structure known as a Quantum Confined Atom (QCA) believe they will become the building block for a range of new semiconductor devices.
A quantum confined atom is an atom or an ion (atom with an electric charge) trapped within a nanocrystal cage (a tiny cage made from the atoms of a semiconductor). In conventional semiconductor technology, most electronic devices are made from layers of different types of semiconductor. The semiconductor materials used are "doped" with atoms of different elements, which alter their properties so that each layer will have the particular electrical characteristics
needed for that type of device to work. QCA technology however is the direct opposite of this. Instead of the trapped atom altering the properties of its semiconductor host, the semiconductor atoms of the cage modify the properties of the atom they are confining.
Nanocrystals researchers are trapping atoms in spaces between 2 and 10 billionths of a meter in size. At present they are concentrating on trapping phosphorescent ions (ions that emit visible light of a certain colour when light of a different colour or invisible ultraviolet (UV) light is shone at them). By reducing the size of these cages from 10 down to between 2 and 5 billionths of a meter, the researchers found the ions could generate 20 times more light. This meant they were emitting as much light as conventional phosphor particles 1000 times larger. This dramatic enhancement of luminescence efficiency is expected to have an impact all optical devices such as light emitting diodes (LEDs), lasers, displays and fluorescent lamps and should be available commercially within five years. In fact, his nanophosphors could find their first application as early as next year, replacing existing phosphors that convert the X-rays used in medical imaging into light so a picture can be recorded. Because they are so small and efficient, the new nanophosphors can improve the resolution of X-ray images, and allow a smaller dose of X-rays to be used while still obtaining a clear picture. Today there is research being conducted to modulate and enhance other properties such as magnetic properties of the nanocrystals. This would mean QCAs could act as storage materials for data in ultra-high-density magnetic recording systems - all of which will soon be required by our computing devices such as, MP3 players, cell phones and laptops.
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