Blue LED
Refers to the blue light-emitting diodes. The center of the emission wavelength is around 470nm. For lighting fixtures and indicators shown in blue part of the light source, the blue light of LED display and LCD panel back-illuminated light source. With the phosphor material combinations available to white light. White LEDs generally use a combination of the structure of the blue LED and the fluorescent material.
led 1w can be widely used the opportunity, Nichia Chemical Industries in December 1993, the first time in the industry, developed a light intensity of 1cd above varieties. Prior to this, there is no blue high purity and has a strong practical light LED. Therefore, the large-size display with LED can not achieve full-color display.
The material of the blue LED using gallium nitride (GaN) semiconductor class. Was prevalent before the blue LED of zinc selenide (ZnSe), semiconductor development, since the GaN semiconductor December 1993 high brightness led power 10w was developed mainstream of the blue LED using GaN semiconductor products.
The blue LED structure on the surface of the sapphire or SiC and base, the semiconductor layer of overlapping laminated aluminum nitride (AlN) and GaN semiconductor layer. Called active layer, the luminous blue part of the set of p-type GaN semiconductor layer and the n-type GaN semiconductor layer overlapping structure.
The pn junction is the structure must be used by the production of high brightness LED. In red and other use of materials other than GaN LED, pn junction long before mainstream construct. Before the 1993 high-brightness blue led 10w available, the use of GaN materials is difficult to achieve the pn junction. The reason is made of n-type GaN semiconductor layer is relatively simple, but the production of p-type GaN semiconductor layer is more difficult. GaN type semiconductor layer between the p-type GaN semiconductor layer and the n-type GaN-type semiconductor layer configuration using multiple quantum well structure, and to further improve the quality of the GaN type semiconductor layer, light strong to obtain a substantial increase.
Green LED
Launch green diode. Luminescence center wavelength at about 560nm. For the neon lights and indicator light of the LED display and LCD panel, the backlight light source.
The green LED and red LED and blue LED, that there are still large room for improvement. Modulated into a high brightness and balanced white of a combination of red LEDs, green LEDs and blue LEDs LED display or LCD panel, the backlight light source, in order to take into account human visual sensitivity, the allocation ratio of the RGB three-color LED light needs about 3:6:1 or about 3:7:1. Due to insufficient brightness of the green LED, so you must use more than one green LED to increase the output power. Green LED is mainly used in GaN-type semiconductor material is lower than the efficiency for the blue LED, enter the same power, the optical output power is low.
This situation began to change. Japan and overseas universities and the LED chip makers and others have started to research by changing the surface of GaN crystal growth, a substantial increase in efficiency. GaN semiconductor crystal surface can be changed, there may be green LED efficiency is increased to more than 2 times.
GaN semiconductor sales green LED inefficiency reasons is that the piezoelectric field. The piezoelectric field of the electric field generated by the piezoelectric polarization resulting from the stress of the crystal structure. The green High Power LED 50W on the market and more based on the polar surface of GaN crystal c-plane (0001) growth surface, its normal direction (c axis) for the growth axis of stratification of GaN semiconductor layer. By changing the growth axis to weaken the piezoelectric polarization of GaN crystal c-plane perpendicular to the non-polar surface as a surface or m-plane or c-plane tilt of the polar surface for the growth of surface per a surface normal direction for the growth axis of the green LED is very active.
Red LED
Launching red diode. Luminescence center wavelength of 620 ~ 630nm. Is mainly used in neon lights, indicators, car tail lights and signal are shown in red part of the light source, the red light of LED display and LCD panel, the backlight light source, a wide range of applications.
At present, the red LED mainstream materials A lInGaP compound semiconductor. AlInGaP the use of four kinds of Al, Ga, In and P elements, known as 4 yuan materials. 4 yuan material in the LED field generally refers to the AlInGaP. Not just red, AlInGaP also covers the wavelength range from red to yellow.
Into the 1990s after AlInGaP brightness is increasing rapidly. This is due to the vapor phase epitaxy MOCVD growth of technical progress, the crystalline quality to improve the results. Before AlInGaP available GaAs class semiconductor mainstream material. The liquid phase epitaxial growth technique.
Nine Advantages of LED flexible light strip
A pure colors: LED flexible light, be used in high-brightness SMD LED as light emitting devices, hence, have the advantages of LED light emitting devices, pure light color, soft, no glare. Both can be used as decorative purposes, they can cater to lighting purposes.
Softness: LED flexible light bar very soft and the FPC substrate can be bent without breaking, easy molding, suitable for a variety of advertising and styling.
Third, the low heat: LED flexible light emitting element is the LED, single LED at low power, usually 0.04 ~ 0.08W, so heat is not high. Can be used as decorative lighting in the aquarium, without generating a lot of heat caused by water temperature, affecting the growth of ornamental fish.
Ultra energy-saving: LED flexible light of Article 1210 of the power is only 4.8W per meter, the 5050 LED flexible light per meter power 7.2W, relative to traditional lighting and decorative lighting, low power several times, but the effect is a lot better.
The composition of materials, environmental protection: LED soft lights regardless of the LED or the FPC, the materials are used in environmentally friendly materials, are recyclable type, caused by environmental pollution and destruction because of the large-scale use.
Security: led power 50w flexible light strip with low voltage DC 12V supply voltage, so very safe to use. Regardless of the elderly, children can be safe to use without causing a safety hazard.
Simple installation: LED soft lights installation is very easy with the clip, the groove, wire, iron nets can be installed in a variety of bearing surface. In addition, LED flexible strip light, thin, and therefore, the use of double sided tape can also be a fixed function. Do not need professionals to install, can really enjoy the fun of DIY decoration.
Eight, long life: LED flexible light strip of normal life is 100,000 hours, 24 hours a day's work, almost all of its life the past 10 years. Therefore, the life of the LED flexible light strip is several times more than traditional lighting.
Nine, a wide range of applications: LED flexible light because the soft, thin, pure color and other characteristics, are widely used in the production floor, body contour, step, stand, bridge, hotel, KTV decorative lighting, as well as advertising signs, a variety of large-scale animation, calligraphy and painting, advertising design, and other places. Flexible LED technology is mature, its scope of application will be more extensive.