The Development and Impact of Blue LED

Why was the development of blue LED crucial for modern lighting technology?

• It was the last missing component needed for white LED lighting

• It replaced incandescent bulbs directly

• It was cheaper to produce than red and green LEDs

• It improved the efficiency of traditional light bulbs

What material is primarily used for manufacturing blue LEDs?

• Silicon (Si)

• Gallium Arsenide (GaAs)

• Gallium Nitride (GaN)

• Indium Phosphide (InP)

What was the major challenge in doping GaN as a p-type semiconductor?

• GaN is too soft and cannot be processed

• Hydrogen passivation neutralized the acceptor dopants

• GaN cannot conduct electricity efficiently

• GaN does not emit photons in the visible spectrum

Which technique was crucial for growing high-quality GaN films for blue LED fabrication?

• Liquid Phase Epitaxy (LPE)

• Metal-Organic Chemical Vapor Deposition (MOCVD)

• Physical Vapor Deposition (PVD)

• Electrochemical Etching

What role does InGaN (Indium Gallium Nitride) play in blue LED technology?

• It acts as a buffer layer to support GaN growth

• It serves as the active layer where electron-hole recombination occurs

• It provides electrical insulation between LED layers

• It is used as a substrate for LED fabrication

Which of the following is NOT an application of blue LEDs?

• High-efficiency white LED lighting

• Blu-ray technology

• Solar cell energy conversion

• Full-color display panels

Why did the 2014 Nobel Prize in Physics go to Akasaki, Amano, and Nakamura?

• They discovered a new method to generate electricity from light

• They developed the first commercially viable blue LED

• They created the first practical white LED

• They discovered quantum dots

What is the main advantage of LED lighting over traditional incandescent bulbs?

• LEDs produce more heat than incandescent bulbs

• LEDs require frequent replacement due to shorter lifetimes

• LEDs are significantly more energy-efficient and have a longer lifespan

• LEDs use tungsten filaments, making them more durable

What is the approximate bandgap energy of GaN, which makes it suitable for blue light emission?

• 1.1 eV

• 2.4 eV

• 3.4 eV

• 5.2 eV

What was the main limitation of early LED technology before the invention of blue LEDs?

• LEDs could only emit infrared and red light

• LEDs required very high power to function

• LEDs were too expensive to manufacture

• LEDs emitted too much heat, making them impractical