• It was hard to find the right material for blue light.
• Red and green LEDs were easier to make.
• Blue light needs more energy to shine.
• Scientists used gallium nitride (GaN) to make blue LEDs.
• GaN was tricky to work with.
• It was hard to grow GaN crystals without defects.
• Making blue LEDs needed very hot temperatures.
• Blue LEDs were finally made in the 1990s.
• They helped create white LED light (red + green + blue).
• Blue LEDs made screens brighter and saved energy.
1. Why were red and green LEDs easier to make than blue LEDs?
2. What material did scientists use to make blue LEDs?
3. What made gallium nitride (GaN) tricky to work with?
4. What might have happened if scientists couldn’t make blue LEDs?
5. Do you think it was worth all the hard work to create blue LEDs? Why or why not?