Reference no: EM131104117
1- Element semiconductors are located in the fourth column of the periodic table of elements, what does make these elements different from other elements?
2- What is the difference between valence electrons in an atom with other electrons?
3- What is the difference between conducting material, semiconductors, and insulators based on their bandgap energy?
4- Compare the bandgap energy between Si and Ge. Why Si has a larger bandgap energy?
5- What is the definition of unit cell in a lattice?
6- What is the difference between a direct bandgap semiconductor and an indirect bandgap semiconductor and provide a few example for each.
7- An orange light emitting diode emits green light in low temperatures, why?
8- What is Fermi Distribution and how does it change with temperature?
9- What are Nc and Nv? And what do they show?
10- What is polysilicon?
11- What is complete ionization? How much energy is required to ionize "B" and "As" in Silicon?
12- Explain what happens when n-type impurities are added to Si.
13- What is the difference between intrinsic and extrinsic semiconductors?
14- Explain the following Figure:
15- Explain the following Figure:
16- In a diamond crystal, the lattice constant, a, is 0.356 nm, what is its atomic density (number of atoms per cm-3)?
17- In a diamond crystal, the lattice constant is 0.356 nm, what is the minimum distance between the atoms?
18- Find the density of electrons and holes in Si if the density of n-type impurity is 1.5ni and the density of p-type impurity is 1.2ni, where ni is the intrinsic density of carriers in Si at T=500K (Hint use Fig. 1.18).
19- Is the semiconductor in question 18 a degenerate semiconductor or a non-degenerate semiconductor?
20- Show eV is an energy unit.
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