Question

1. ______________ bandgap semiconductors such as Si are inefficient for photon generation (e.g., in diode lasers and LEDs) since their conduction and valence bands are not lined up at the same momentum (E vs. k) 2. Devices (such as lasers) often use structures based on layers of semiconductors with different bandgap energies. What is the term used to describe devices based on different bandgap materials? __________________ 3. A bond commonly formed in semiconductors where adjacent atoms share two electrons is called a _________________ bond. 4. The factor that describes the ability to convert photons to current (photodetector) or current to photons (lasers, LEDs) is called ___________ efficiency. 5. What type of photodetector is biased very close to the breakdown voltage to make use of the internal gain mechanism? _____________________________.

Answer 1

1. Indirect bandgap semiconductors such as Si are inefficient for photon generation (e.g., in diode lasers and LEDs) since their conduction and valence bands are not lined up at the same momentum (E vs. k).

2. Devices based on different bandgap materials are called Compund Semiconductors.

3. A bond commonly formed in semiconductors where adjacent atoms share two electrons is called a Covalent Bond.

4. The factor that describes the ability to convert photons to current (photodetector) or current to photons (lasers, LEDs) is called Quantum Efficiency.

5. The type of photodetector is biased very close to the breakdown voltage to make use of the internal gain mechanism is called Avalanche Photodiode.