LED (light emitting diode)

Contents show

What is a LED?

LED is an acronym that stands for light-emitting diode. Inside each LED there is a semiconductor that reacts to a continuous voltage source, generating light; this process is known as electroluminescence. Different types of LED can be created depending on the manufacturing and circuitry assembly technology used.

LED technology

A LED’s light-emitting operation is based on the activation of an inorganic semiconductor due to an electrical current. Depending on the compound used for the semiconductor, different types of light emissions and colors can be achieved. Take a look at the list below, where you will find the most common LED colors and their semiconductor composition:

COLOR	WAVE LENGTH (NM)	COMPOUND
INFRARED RADIATION	λ > 760 NM	Gallium arsenide (GaAs) Gallium-aluminium arsenide (AlGaAs)
RED	610 NM < λ < 760 NM	Gallium-aluminium arsenide (AlGaAs) Gallium arsenide phosphide (GaAsP) Gallium-indium-aluminum phosphide (AlGaInP) Gallium phosphate (GaP)
ORANGE	590 NM < λ < 610 NM	Gallium arsenide phosphide (GaAsP) Gallium-indium-aluminum phosphide (AlGaInP) Gallium phosphate (GaP)
YELLOW	570 NM < λ < 590 NM	Gallium arsenide phosphide (GaAsP)) Gallium-indium-aluminum phosphide (AlGaInP) Gallium phosphate (GaP)
GREEN	500 NM < λ < 570 NM	Gallium phosphate (GaP) Gallium-indium-aluminum phosphide (AlGaInP) Gallium-aluminium phosphide (ALGAP)
BLUE	450 NM < λ < 500 NM	Zinc Selenide (ZnSe) Indium gallium nitride (InGaN) Silicon carbide (SiC) as a substrate
VIOLET	400 NM < λ < 450 NM	Indium gallium nitride (InGaN)
ULTRAVIOLET	570 NM < λ < 590 NM	Indium gallium nitride (InGaN) (385-400NM) Diamond (c) (235NM) 73 Boron nitride (BN) (215NM)74 75 Aluminum nitride (ALN)(210NM)76
RED	COMBINATION OF SEVERAL	Blue with one or two layers of phosphorus Yellow with red, orange or pink phosphorus
WHITE	Wide spectrum	Zinc Selenide (ZnSe) Indium gallium nitride (InGaN) Silicon carbide (SiC) as a substrate

LED’s applications and uses

The first successful commercial use for LED-based technologies began with the infrared diodes commonly used in remote controls of all kinds of devices. However, LED-based technology is currently widespread across several industries.

The success and acceptance of LED-based lighting systems is due to its long lifespan, low energy consumption and great durability.

The advancement in LED-based technology has led to the creation of large sized LED screens, such as the ones placed in crowded areas used for advertisement and as information boards.

Due to its many benefits and advantages over traditional systems, it is no wonder that LED screens have become attractive for consumers and an attraction for the public; as we keep seeing an increased adoption of this technology in our streets and avenues.

LED Types

DIP LED

High environmental resistance
High brightness levels
Better colour fidelity and definition than conventional DIP LEDs
Unique 3-colour encapsulation

SMD LED

Better vision at close distances
Unique encapsulation of the 3 colours
Better picture definition

ANTIVANDALIC LED

Same advantages as SMD LED
Additional protection dome against impact or extreme environments

There are several types of LED-based technology for advertising LED screens:

LED DIP (Dual in-line package)

A highly resistant encapsulated LED that only emits one color. Commonly used in LED panels forming the RGB tricolor set (any color can be created with a combination of these three). These LEDs are a good option for outdoor LED screens, as they resist environmental wear and have great luminosity. The only drawback is their reduced viewing angle.

SMD LED (Surface-Mounted Device)

SMD LEDs combines red, green and blue (RGB) in a single package. This allows for smaller pixels with good viewing angles. While SMD LEDs are used for both indoor screens and outdoor screens ,they tend be less resistant and dimmer than the DIPs.

Vandal resistant / Outdoor resistant LED

Combining the strength and durability of the DIP LED with the versatility and definition of the SMD LED, this technology has an additional protective encapsulation that protects the LED’s semiconductors. This is the reason why it is more expensive than the SMD or DIP LEDs.