Can a light emitting diode be exposed to the atmosphere or water and still function?

Question

i am referring to the elements of the diode being exposed...i know you can put a diode under water.

Answer 1

Yes, if not that long.  Just don't let the contacts corrode or the LED is no good.

Answer 2

Yes,

LEDs are constructed out of plastic and therefore are safe under most conditions.  The electrical link must be sealed away from the water, but I am assuming that you know that.

A chlorine atmosphere or some other corrosive atmosphere would seriously degrade an LED and might eventually dissolve it.

According to Wikipedia:  http://en.wikipedia.org/wiki/LED#Materia...

"Conventional LEDs are made from a variety of inorganic semiconductor materials, producing the following colors:

Aluminium gallium arsenide (AlGaAs) — red and infrared

Aluminium gallium phosphide (AlGaP) — green

Aluminium gallium indium phosphide (AlGaInP) — high-brightness orange-red, orange, yellow, and green

Gallium arsenide phosphide (GaAsP) — red, orange-red, orange, and yellow

Gallium phosphide (GaP) — red, yellow and green

Gallium nitride (GaN) — green, pure green (or emerald green), and blue also white (if it has an AlGaN Quantum Barrier)

Indium gallium nitride (InGaN) — 450–470 nm — near ultraviolet, bluish-green and blue

Silicon carbide (SiC) as substrate — blue

Silicon (Si) as substrate — blue (under development)

Sapphire (Al2O3) as substrate — blue

Zinc selenide (ZnSe) — blue

Diamond (C) — ultraviolet

Aluminium nitride (AlN), aluminium gallium nitride (AlGaN), aluminium gallium indium nitride (AlGaInN) — near to far ultraviolet (down to 210 nm)

With this wide variety of colors, arrays of multicolor LEDs can be designed to produce unconventional color patterns."  

However they can be covered with plastic and cheaply made OR they can be covered in glass which is stable under most chemical environments; even when exposed to chlorine gas and other corrosive gases.

In addition you can seal your LED BEHIND something transparent and water tight like plastic or glass so that the state of the electrical connections don't matter.

Answer 3

Yes, but it is the connections that will be the weak link.

Answer 4

maybe a while, as the surface is passivated and quite non-reactive. Air, it would be ok until contamination would short it out.

Water, if pure, it would be OK, but any impurities in the water that makes it conductive would also short it out.