Laser diode emits deep UV light

Nagoya University scientists, in cooperation with Asahi Kasei Corporation, have designed a laser diode that emits deep-ultraviolet light, and have published a paper in the journal Applied Physics Express.

Colloidal quantum dot laser diodes are just around the corner

Los Alamos scientists have incorporated meticulously engineered colloidal quantum dots into a new type of light emitting diodes (LEDs) containing an integrated optical resonator, which allows them to function as lasers. These ...

Halfway toward LHC consolidation

The Large Hadron Collider is such a huge and sophisticated machine that the slightest alteration requires an enormous amount of work. During the second long shutdown (LS2), teams are hard at work reinforcing the electrical ...

Improving efficiency, brightness of perovskite LEDs

Advances in organic phosphorescent materials are opening new opportunities for organic light-emitting diodes for combined electronics and light applications, including solar cells, photodiodes, optical fibers and lasers.

Tuning the energy levels of organic semiconductors

Physicists from the Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and the Center for Advancing Electronics Dresden (cfaed) at the TU Dresden, together with researchers from Tübingen, Potsdam ...

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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.

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