Gandhinagar Institute of Technology

PHYSICS(2110011) Active Learning Assignment(ala)

Topic: blue led

Guided By: Prof. NIRAV PANDYA

Branch : Electrical EngineeringDiv: F(G1)

Group member:

>Darshil Shah(140120109050)>BHUSHAN BORSE(140120109002)>Krupal Patel(140120109034)

The History of LED’S•1929 - Soviet patent granted for a “ light

relay.”•1961-Modern LED invented at Texas

Instruments.•1962 -Red LED invented.- First mass

produced “indicator lights.”• 1990-First blue LED with vastly

increased light output. • - RGB becomes practical. • - mainly used theatrically.

Blue Led’s -Filling the world with a new light• Isamu Akasaki, Hiroshi Amano and

Shuji Nakamura are rewarded for inventing a new energy-efficient and environment friendly light source- the blue light emitting diode (LED) in early of 1990’s.

• In the spirit of Alfred Nobel, the prize awards an invention of greatest benefit to mankind; by using blue LEDs, white light can be created in a new way.

BLUE LED

Making of Blue LED

•Gallium nitride (GaN), which is the material used to create blue LEDs, is hard to grow. In order to make an LED you need to make a P-N junction, meaning a layer of p-type material (positively doped) on top of n-type material (negatively-doped).

Gallium Nitride> Gallium nitride is

used in blue led. The molar mass of gallium nitride is 83.73 g/mol

> Band gap of gallium nitride is 3.4 ev (300 k,direct)

Circuit Diagram of Blue Led:

BLUE LED for Saving Energy and Resourses• A light-emitting diode consists of a number of layered semiconductor

materials. In the LED, electricity is directly converted into light particles, photons, leading to efficiency gains compared to other light sources where most of the electricity is converted to heat and only a small amount into light. In incandescent bulbs, as well as in halogen lamps, electric current is used to heat a wire filament, making it glow.

• The new LEDs require less energy in order to emit light compared to older light sources. Moreover, they are constantly improved, getting more efficient with higher luminous flux (measured in lumen) per unit electrical input power (measured in watt).

• The most recent record is just over 300 lumen/watt, which can be compared to 16 for regular light bulbs and close to 70 for fluorescent lamps. As about one fourth of world electricity consumption is used for lighting purposes, the highly energy-efficient LEDs contribute to saving the Earth’s resources.

PUPOSE OF BLUE LED • Although red and green LEDs had been around for

many years, blue LEDs were a long-standing challenge for scientists in both academic and industry.

• White LED lamps, meanwhile, deliver light to many offices and households. They use much less energy than both incandescent and fluorescent lamps.

• In the future, engineers may make white LEDs by combining red, green, and blue ones, which would make a light with tunable colors, the Nobel Committee wrote.

Images of BLUE LED

Applications

• Status lights.• Off / on indicator.• Background illumination.• Readout lights.• Maintenance lights.• Legend light.

REFERENCES•Wikipedia of Blue LED.• Google.

Thank You