Energy & Green Tech

Powering devices—with a desk lamp?

Batteries power most of our devices, and even some cars. But researchers now report in ACS Applied Materials & Interfaces a step toward running electronic devices in homes and offices on the light coming from lamps scattered ...

Engineering

Smart transformer for the energy turnaround

A new, smart medium-voltage transformer developed at ETH Zurich features cutting-edge semiconductor technology, making it extremely compact and energy efficient. Future applications are ranging from locomotives to fast charging ...

Engineering

Smart windows could combine solar panels and TVs too

Imagine standing in front of a wall of windows, surveying the view. You hear someone enter the room behind you. You turn. "Welcome," you say. "Here is the video I wanted to show you." At the press of a button, the view vanishes ...

Engineering

Team focus is on ultrasound window into the human body

(Tech Xplore)—A surgeon diagnosed his own cancer with the help of a phone. That is the attention-grabbing line that has turned people's attention to a new device to ship next year. It is the Butterfly iQ, a portable ultrasound ...

Semiconductors

Engineers develop powerful millimeter-wave signal generator

Your doctor waves a hand-held scanner over your body and gets detailed, high-resolution images of your internal organs and tissues. Using the same device, the physician then sends gigabytes of data instantly to a remote server ...

Semiconductors

Chemical etching method helps transistors stand tall

Smaller and faster has been the trend for electronic devices since the inception of the computer chip, but flat transistors have gotten about as small as physically possible. For researchers pushing for even faster speeds ...

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Semiconductor

A 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, solar cells, 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. This process is called "doping".

This text uses material from Wikipedia, licensed under CC BY-SA