LED is an abbreviation of Light Emission Diode, and is a device which emits light by flowing a current to the p-n junction like a semiconductor laser
What is the benefit of the emitted light in an LED?
Compared with conventional light sources that first convert electrical energy into heat, and then into light, LEDs (Light Emitting Diodes)
convert electrical energy directly into light
, delivering efficient light generation with little-wasted electricity.
What does an LED emit?
A light-emitting diode (LED) is a semiconductor light source that
emits light when current flows through it
. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons.
What is the most commonly used color of an LED?
Light emitting diodes are available in a wide range of colours with the most common being
RED, AMBER, YELLOW and GREEN
and are thus widely used as visual indicators and as moving light displays.
Why is LED not made of silicon or germanium?
LEDs are p-n junction devices constructed of gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), or gallium phosphide (GaP). Silicon and germanium are not suitable
because those junctions produce heat and no appreciable IR or visible light
.
What are the disadvantages of LED lights?
- High up-front costs.
- Transformer compatibility.
- Potential color shift over lamp life.
- Performance standardization has not yet been streamlined.
- Overheating can cause reduced lamp life.
What are the side effects of LED lights?
Little wonder that many people complain of itchiness,
redness in the eyes and mild headaches
after continuous exposure to LED lights. The AMA says that life-long exposure of the retina and lens to blue peaks from LEDs can increase the risk of cataract and age-related macular degeneration.
What are the cons of LED lights?
Perhaps the biggest drawback of LED light bulbs is that they
emit more blue light than
incandescent bulbs, which are more on the red end of the spectrum. Blue light can cause a disruption in your circadian rhythm, negatively affect your ability to fall asleep and the quality of your sleep.
What is the most relaxing color for LED lights?
A 2017 study reported in the scientific journal PLOS ONE (3) found that
blue lighting
leads to post-stress relaxation three times as quickly as conventional white lighting. Blue light’s potential calming effects have been observed outside scientific studies as well.
What color LED light is best for your eyes?
Yellow light
is the best contrast against blue light and can protect the retinas of the eyes.
What do different color LED lights mean?
The lower the color temperature, the warmer the light will appear
, or the redder it will appear. The higher the temperature, the cooler the light will appear, or the bluer it will look.
What should be biasing LED?
5. What should be the biasing of the LED? Explanation: The LED works when
the p-n junction is forward biased
i.e., the p- side is connected to the positive terminal and n-side to the negative terminal.
Why Silicon is not used in fabrication of LED?
Since Silicon is an Indirect Band Gap semiconductor so electron cannot fall directly to the valence band but must undergo a momentum change as well as a change in energy. So,
energy is released as heat along with the light
. Hence, silicon is not suitable for the fabrication of LEDs.
Why don’t we use germanium in semiconductors?
As we all know, both Silicon and Germanium are semiconductor devices. … The structure of
Germanium crystals will be destroyed at higher temperature
. However, Silicon crystals are not easily damaged by excess heat. Peak Inverse Voltage ratings of Silicon diodes are greater than Germanium diodes.
Why are LED lights bad?
A 2012 Spanish study found that LED radiation
can cause irreversible damage to the retina
. A 2019 report from the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) warned of the “phototoxic effects” of blue light exposure, including an increased risk for age-related macular degeneration.
When should you not use LED lights?
Enclosed fixtures that don’t allow for proper ventilation can drastically affect the temperature of the LED bulb, causing it to
overheat
and shortening the lifespan of the bulb. That’s why some bulbs will tell you not to use it in an enclosed ceiling fan or fully enclosed porch light fixture.
