Electronics & Semiconductors

A combined optical transmitter and receiver

Researchers at Linköping University, together with colleagues in China, have developed a tiny unit that is both an optical transmitter and a receiver. "This is highly significant for the miniaturisation of optoelectronic ...

Engineering

New technology: Hygienic beer caps

UV light inactivates germs in drinking water. Until now, the disinfection process relied on mercury-vapor lamps, which emit light in the UV spectrum. However, mercury is a heavy metal that affects human health and the environment. ...

Energy & Green Tech

Developing technologies that run on light

The future of faster, more efficient information processing may come down to light rather than electricity. Mark Lawrence, a postdoctoral scholar in materials science and engineering at Stanford, has moved a step closer to ...

Engineering

Converting Wi-Fi signals to electricity with new 2-D materials

Imagine a world where smartphones, laptops, wearables, and other electronics are powered without batteries. Researchers from MIT and elsewhere have taken a step in that direction, with the first fully flexible device that ...

Consumer & Gadgets

Samsung is working on laptop with foldable display

Laptops with folding screens? Never say never when the visionaries at Samsung get excited far beyond words, such as "Signing off, see you in the morning."

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 ...

Energy & Green Tech

Knitting electronics with yarn batteries

When someone thinks about knitting, they usually don't conjure up an image of sweaters and scarves made of yarn that can power watches and lights. But that's just what one group is reporting in ACS Nano. They have developed ...

page 1 from 2

Diode

In electronics, a diode is a two-terminal device (thermionic diodes may also have one or two ancillary terminals for a heater).

Diodes have two active electrodes between which the signal of interest may flow, and most are used for their unidirectional electric current property. The varicap diode is used as an electrically adjustable capacitor.

The unidirectionality most diodes exhibit is sometimes generically called the rectifying property. The most common function of a diode is to allow an electric current in one direction (called the forward biased condition) and to block the current in the opposite direction (the reverse biased condition). Thus, the diode can be thought of as an electronic version of a check valve.

Real diodes do not display such a perfect on-off directionality but have a more complex non-linear electrical characteristic, which depends on the particular type of diode technology. Diodes also have many other functions in which they are not designed to operate in this on-off manner.

Early diodes included “cat’s whisker” crystals and vacuum tube devices (also called thermionic valves). Today most diodes are made of silicon, but other semiconductors such a germanium are sometimes used.

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