Question:
What is the minimum band-gap of the LED diode?
What is the minimum band-gap of the LED diode?
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For visible light emission, an LED must have a band-gap of at least 1.8 eV.
Updated On: Apr 23, 2025
- 1.5 eV
- 1.7 eV
- 1.8 eV
- 0.8 eV
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The Correct Option is C
Solution and Explanation
LEDs (Light Emitting Diodes) emit light when electrons recombine with holes, releasing energy equal to the band-gap. The visible spectrum starts from around 1.8 eV (for red light).
- Below 1.8 eV: Not enough to emit visible light.
- Above 3 eV: Emission shifts to UV region.
So, 1.8 eV is the minimum band-gap needed to emit visible light.
- Above 3 eV: Emission shifts to UV region.
So, 1.8 eV is the minimum band-gap needed to emit visible light.
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